I have used the Garmin nuvi 2555LMT 5-Inch GPS Navigator with Lifetime Maps and Traffic for several months now. It is quite good, but has some issues you should be aware of. This GPS as well as the same model with a 4.3-inch screen were Consumer Reports "best buys", and that is the reason I bought it.
I used to have a 3.5-inch CRT TV-like Garmin c320, that not only looked unappealing and had a small screen, but it also stopped working in my car after I installed the DVR/camcorder. When I bought this Garmin nuvi, I was happy that it worked and locked onto GPS signals faster than the c320.
Also good was the mounting hardware. Not only is this navigator thin and modern-looking, its mounting hardware (suction cup and the bracket) are sturdy and easy to use. Additionally, the screen is large, bright and informative. The 12V power cable has a built-in receiver for the traffic information.
On another hand, the suction cup keeps coming off. I might have to get another mounting device, e.g. a friction mount.
The Garmin nüvi 2555LMT comes with lifetime map updates and free lifetime traffic. It has features like junction view, lane guidance, split view of map/junctions, speed limit display in some areas.
First off, the reception is quite good and the signal is obtained faster than that of the previous GPS devices I used. The directions are easy to follow and the traffic alerts are visible at all times. The ETA (estimated time of arrival) takes into account traffic conditions en route. And if you want to go around the traffic, you are presented with choices and estimated times. Nice.
The sounds and markings are informative. The route calculation and re-calculation is pretty fast, but not very much so. It takes several seconds. The 5-inch screen is huge, bright and informative.
The Garmin nüvi 2555LMT powers up when you turn the car on and turns off when you turn it off, so that is nice and unlike the stupid TomTom One (or is it Tom Tom?), which you have to turn on and off yourself.
The traffic information works at times and sometimes there is a traffic jam on the freeway and you are stuck in it, but the GPS shows you "all clear". In other words, the data may be out of date. Still, it is better than nothing.
Speed Limit Information
This is quite problematic. On one the part of the freeway I take almost daily and where the speed limit has been 55 mph for at least several years, the GPS tells me that the speed limit is 45 mpg, for a good 2 miles. On some streets in Irvine, where the speed limit has been 55 mph for at least 6 years, it states that it is 45 mph or 50 mph. And, worse, in some areas where the limit is 45 mph, it claims that it is 50 mph. So it is accurate to +/- 10 mph, and as such worse than useless.
This Garmin nüvi 2555LMT is an excellent GPS as long as you don't rely on its speed limit guidance and do not expect the traffic information to be very accurate. Its lane guidance and junction view came in handy many times. I use it all the time and highly recommend it.