Price: $399.95 $281.47

Clear and very accurate and much better than the Magellan 4000.
Missing a compass and speech quality needs improvement.

I purchased this unit last week because I had kind of been looking at them and was preparing for a 1400 mile trip so I decided to go ahead and get it. I had read C-net's reviews and they ranked this as one of the top 6 GPS must have units. I was impressed by the looks and features offered. I wanted bluetooth capability which this unit had and not many others at this price point. I had a few days to try it out around town and on my trip and I am extremely dissapointed. First off and probably the biggest issue is the unit is very inaccurate, I would estimate about 1/2 mile off. Not a big deal when you know your destination but if looking for a specific address it is a major flaw. It does not tell you what side of the street your destination address is on, not sure if other units do. When exiting from one highway to another where you could go multiple directions it does not tell you the direction you need to go until after you exit. Once again not a big deal if there are two exits like 12A and 12B but if there was one exit with a split, this could be a major issue, especially if it were like a spagetti bowl where it was not a simple left or right deal.
Bluetooth performance, one of the reasons I purchased this unit because I had been considering a handsfree car device already, is almost unusable. The functionality of it is excellent and I had no issues paring it with my RAZR V3xx, or downloading my address book like many have mentioned, but the volume is so low you can't hear the person you are talking to over road noise and they can't hear you. There is also no way of adjusting the default volume, which is about 1/2, on the bluetooth so before I realized it was useless I found myself quickly trying to raise the volume on each call.
The unit has a couple of neat features like the ability to mark stationary traffic monitoring devices like red light cameras. The problem is that once marked it doesn't notify you in any way that the camera is there, it just places a tiny camera icon at the location you marked so unless you happen to be looking very closely at the map when you approached the location you wouldn't be aware. The unit is supposed to have many known devices already marked but after driving around a city with many of them, I have found none pre-loaded. Other neat features like warnings of your speed don't seem to work either. The device has the ability to show the speed limit of the road you are on, if known, but I have found no streets that show the speed limit, even major interstates that traverse the country. You can also set an "alternate" max speed and have the unit warn you if you exceed that speed by a set threshhold. I did this and exceeded that speed well beyond the set tolerance many times and it gave no warning. I did have the above features enabled in the settings.
Support on the device is horrible. There is no reference in the manual or on the company web site about when map updates, or expansions are available, how to get them, or if there is a cost involved. I have read on some forums that there is a cost for any map updates. The unit also had the ability to get live traffic updates when used with an optional cradle. Once again, no mention of if/when this cradle is available, the cost or of it at all actually on the website. You can subscribe to the traffic service though, ha.
The unit does have a farily extensive POI database, even compared to other units. After initially setting the POI categories I wanted to see, I could not figure out how to further alter them. I initially selected to show asian restaurants but I never knew just how many of them there actually are! There is a category for "my poi" and In the manual it says there is an application on the CD that allows you to import your own POIs from a spreadsheet, or to import up to date lists. My CD did not come with this application and of course, there was no download for it on the website.
The unit has some other negatives that may just be me nitpicking. Like it only comes with a quick setup guide, the full guide is on the CD. For a device like this that is used primarliy away from a computer, I expect a full manual so it could be referenced when you are on the road and have a question, like happened to me many times. I would also like the ability to set more than 2 favorite destinations. Currenly you can set home and work and unless any other favorites happen to be in your history you have to re-enter the address. I personally don't know any addresses other than work or home and would assume that most who would need a GPS would either. You can import your outlook address book including addresses but getting to them and back to the map is a pain. You have to exit the map application to get to the address book and once the address is found you have to restart the application which takes a minute or 2. Additionally the DC cord is a little short for larger vehicles limiting mounting options.
Bottom line, this unit has great potential, it looks great and has a great interface. It was nice to have on my road trip simply for the ETA and GPS speed functions (I have larger tires so my speedo is off). Most of the issues I have listed could probably be fixed with a software update but like I stated earlier the manufacturer gives no indication of if or when one is coming, or even acknoledges any of the issues in any of the FAQs even though most are being discussed extensively on the GPS forums. Since I don't know when or if my unit will be patched to function properly, I will be returning it and I can't recommend it to anyone else.

I have been using this device for at least 6 months now and have been experiencing some annoying problems, now I feel compelled to share my experience and thoughts about this unit. The pros are pretty common knowledge and have been listed by many other reviewers, so I will not repeat them here. I'll just list the cons that I have not seen mentioned by anyone else. Some problems are just dangerous if you follow the instructions without double checking them.


Cons:
1) Out of date map data - I was looking for Blockbuster closest to my position, and it took me to one that was no longer there. Searching for a restaurant a friend had been going to for years returned no result.

I was looking for a street in Chino, CA. But the C520 shows that are only 2 streets total available in that city. I checked the Tom Tom and Mapopolis on my PDA, and there are more than 2 streets in Chino, and I had the Tom Tom and Mapopolis prior to the Mio. Makes you wonder how out of date the map data on the C520 is.

2) DANGEROUS INSTRUCTIONS - The device has told me to head into incoming traffic on Santa Monica Blvd. I was following the directions from W. LA to a pool hall in Hollywood. Following the instructions, I was on Santa Monica Blvd, it told me to make a left at an intersection, then make an immediate right into Santa Monica Blvd again. Looking at the highlighted directions on the unit, it wanted me to head into the other side of Santa Monica Blvd on the other side of the center divider, in other words, into incoming traffic. This happened to and from the pool hall. Good think I double checked before I followed its instructions.

3) On road where you have to make a 360 degree turn, the instructions can be confusing, the best bet is to look at the highlighted road on the screen. For example, to get on the 57 South freeway in Placentia off Orangethorpe, I was supposed to get onramp on the right hand side, follow it for 360 degrees to get on, but the device verbally told me to make an sharp left, the arrow showed me to make a left. Another example was in Irvine, it told me to get off the 5 South, turn right, then get back on the 5 North. Turned out that I was supposed to turn 360 off the ramp, then follow the side road to my destination.

4) Route recalculations for no darn reasons - I would be following the instructions to the teeth on a route that I know well, and all of a sudden, it would recalculate the route and give me the same route again. I double checked and I was on the route highlighted by the device, so why was it recalculating. This can be annoying, one time I was close to throwing it out the window.

Overall, I still like this unit for many of its pros, and I hope someone will find this review helpful in making their purchasing decisions.

I just noticed today that the addressing system seems to be off by 1/2 mile. For example, search for the address at 3600 W Orangewood, 92868 on the C520 vs Google or Yahoo maps. The first time I was looking for a POI here, I thought it had been moved and the POI was out of date. Now, it makes me wonder if the other POI's which I thought were out of date were actually displayed off the mark by the C520, leading me to believe that the POI had moved.