What is the best GPS for car use in the US?

I'm planning to do a road trip across the US and plan to buy a top-of-the-line GPS unit. I would like something with touch screen, speech capabilities, traffic information, MP3 and bluetooth capability, etc. I will primarily use this for my car but I do have a motorcycle too. But I'd rather have a better car GPS than one that is car+motorcycle friendly if I had to choose between the two. Two models I am looking at are the Garmin StreetPilot 2820 and the Garmin Zumo 550. I'm leaning toward the Zumo 550 as it seems to be better than the StreetPilot 2820 in almost every way. Can anyone out there shed some light on why I would opt for the StreetPilot 2820 instead of the Zumo 550 or why I should go with a different brand/model? I'm a first-time car GPS buyer and have seen neither Garmin product in person. (All of the stores around here carry only the lower end models.) Thanks!|||Garmin StreetPilot 2820|||I have a Garmin Nuvi 350, which most of the features you asked about except bluetooth. The Nuvi 360 has bluetooth capability so you can connect it to your cell phone for hands-free use. The reviews on it are all very positive, one of the unique features being that the voice will read the names of streets, saying "turn right on main" instead of "turn right at the next street." Sorry I don't know much about the other models, but I've been really happy with my Nuvi.|||If you want top of the line i suggest the 2820 as it not only comes with bluetooth but is also expandable with xm satelite radio functionality. It also plays mp3s and audio books. Top of the line stuff.





If you are driving across the country you would do better with the 2820's AC power source since the zumo has only has a rechargable lithium battery that lasts anywhere between 4 and 8 hours. Zumo's great for short trips, but for continuous use over the long haul the 2820 wins out in my opinion.