I used the Quest on a pror Electra Glide. Eveyone is right, the mount sucks, it does come ulocked from vibraion. I actually had a custom mounting lock plate milled with stainless steel which fixed that issue. It was a mojor PITA.
On my 07 SE Ultra, I tried my Garmin Quest 660 I normaly use in our auto. I used the window suction mount on the windsheld and also secured it with a teather in case suction came loose. Guess what, I've been on several hundred miles rides and the suction never has failed. Impressed and suprised me. The added bonus with this arrangment, no holes anywhere which is actually 3-holes not one, very portable, and MP3 music which actually sounds damn good.
The Garmin Nuvi is not water proof, so in rain your going to want to remove i quick, other than that, the unit works really good. On some of my tirps i programed the Harley Dealer locations in case i needed emergency service or maybe a t-shirt..
If you have one intended for you auto, try it on your Ultra.. You will get hooked.
PS. I have the Garmin Quest unit in a box collecting dust.. if anyone wants to buy it cheap, mount and all, ping me off line... kirk@starstream.net
Hope this is allowed.