I've read through allot of the threads on GPS units and most seem to use either the Garmin 276C or the 2610, what are the main differences and the pros and cons to each? Does one hold up to moisture or vibrations on a bike better? Is the 2620 worth it or is the only difference from the 2610 just that it comes with city navigator? I'm going on a trip to Oregon soon with the wife and thought an autorouting GPS would be real nice to have especially when traveling at night when road sighns are hard to read and something that I could attach to my GS, just something nice to have not needed. So whats your advice on what GPS to get and what website has the best service/prices? I see on gpsdiscount.com I can get a refurbished 2610 for $530 or should you stay away from a refurb. What accesories will I have to buy, unless I get the 2620 I'll have to get city navigator or city select, which one should I get for the unit.