My dealer is offering a Nav II for $350 with an '06 I am thinking of getting. Is it still worth this much, or should I spend the money and get a Zumo 550 or Nav III? Thanks
A lot of cost reductions on all sorts of navigators these days -- I think I'd go for the latest and greatest thus commanding as much potential as practical to extend it's useful life.
Although you can use a II off bike, you should be able to find one you can easily deploy in a lot of different vehicles (if that's important to you) and with more features that the II for 100USD more than that offer. If motorcycle focus isn't important (such as being waterproof) then you can spend a lot less even.
Also, you'd want to get the latest maps. If you buy a new nav, you'll typically receive either the latest maps or the potential for a low cost / no cost map data upgrade path within a certain period of the purchase date. That alone is worth about 70USD (ex Garmin 2009 update at retail) and you've taken care of all but 30USD of the difference.
Consider the Zumo 450 or 550 or a Garmin 2820 as viable alternatives.