all garmins have the same interface and will produce the same routing/directions. decide if you want larger screen, speech input, bluetooth, annouced streets (annoying to me), lane guidance (too much hand holding for me), etc. also keep in mind that real-time traffic updates is a subscription feature so you'll have to pay extra for it once the bundled subscription expires.

btw, also check out tom tom since they get good reviews also. i'm picking up a tom tom 720 for $250 saturday (hopefully it will still be in-stock).