I have been using CoPilot ever since it came out for Android. I have tried others, including Garmin's Navigon, but I keep coming back to CoPilot.
It is very accurate, Map updates are free for life, and the POS's are updated with each map upgrade. Downloading all the maps took awhile, even on my wi-fi connection, but it's better than having to depend on a 3g connection to get your maps. I also like the fact that it is easier to transfer to other android devices than the old version. I have it loaded on both my ZTE Warp and my Asus Transformer, both work great.
I almost paid for Navigon by Garmin. I contacted their customer support first to ask about map upgrades. They wouldn't reply. I took the time to search their website, found out that they charge for their map upgrades. You get one free upgrade if you are a new customer. And the quality of their maps and software....well I went back to CoPilot and I am happy with their customer support, they always reply to my questions. Use a larger micro sd card and move CoPilot and maps to sd. No lag in the program.
I traveled all over the US last summer by car, and I used CoPilot on my old phone, which was a HTC Evo 4g. Drove from Colorado to Florida, New York, Texas, California, Kansas, Utah and other places. It didn't make a wrong turn.
Great GPS program for tablets also if the tablet has GPS.
My ZTE Warp, seems to be working fine so far. I plan to travel again this summer.