So reading all of this, I find myself asking, how much do you really need turn-by-turn navigation? Can't you take a look at a map and know where to go? The best solution is probably something like a Garmin Edge that will allow you to plug in a route and direct you (the 500, w/o maps, and 800, w/ maps, can do this) and then have a cell phone with a GPS app that has offline maps, such as Navigon, on your phone for those times you go off course. I cannot see any advantage of having a 7" screen sitting on your handlebars. It would be difficult, and likely dangerous, to use/read while riding, susceptible to bad weather/conditions, and prone to break if the bike ever falls. Not to mention the theft aspect. I'm a gadget junkie and a tech freak, but the tech has to make sense and not get in the way.