So i finally got my zumo 660 mounted a week or so ago and took some pictures to show the final solution I came up with.
For my normal day to day riding, I have it mounted with a special RAM ball stem mount custom made by Jim Winchester (example pics and contact info here ).
The mount is stable as all get out and easily wired in. I use the normal length ram connector with the locking hub to make sure no one steals my bracket (though what they would do with it without the actual GPS is beside me). This zumo doesnt need a screw, but instead has a quick action disconnect and a cover for the electrical connections when the GPS is gone.
I think this location is optimal for two reasons: The first is that it has 0 vibration... the screen is prefectly legible at all RPMS. Second its location brings it much closer to your view and reach. You can operate all the functions of the devise smoothly while driving one handed and you are not stretching or shifting your riding position whatsoever. This also places the device in a position where it blocks your view of nothing on the bike (save the key ring). I took the pictures from my eyes view, while sitting on the bike so you can see the POV... all you have to do is shift your eyes down, you dont even have to move your head.
I did have another dilemma in that I sometimes ride with the RT tank bag and thought this position would be too low... When the mount was installed, enough slack on the wires existed such that I could move it to either reservior RAM ball mount, left or right, depending on which hand i liked operating it with. It turns out, that with the 5" Ram arm, it will clear the tank bag just fine as well. The only other adjustment is that it needs to be tilted slightly back. I have included pictures of this for perspective. Now I can use the other RAM mounts for other toys, like my iPhone or cup holder
As for the device itself, I cant rave enough about it. I threw a 16GB memory chip in it for music and audiobooks -- that maps are all on its own 4gb (I think) storage -- with its direct audio wiring for headphones it works perfectly, coordinating GPS and music. My phone is still blu-toothed, and I can pull over to talk, but I havent wired in my helmet mic yet (though their is a port for it). In fact my N103 with blu tooth and such is now a big waste of money as I dont use its speakers or mic anymore. I may try to figure out a solution for this or I may not.
The garmin software continues to be slick as hell... someone posted about not being able to find places correctly on this... I have seen the opposite -- google maps on my iphone is wrong while the gps is right.
Some have made comments that the route selection is not the best. I think that this is because the Garmin will give you the calculated fastest or the calculated shortest (or if you are off road in your GS the direct shot), but it wont figure out that mix of fastest and shortest that you speed to in order to make the best time. But you can put your custom route in the GPS if you want. Also, the GPS will remember (and leave up on the screen, in a complementary color, the way you just came (for about 25 miles or so) so if all else fails you can back track. Finally its trip loggin is fantastic, allowing you to go on a ride, and then download your stats and where you went.. pretty slick. Every day I find out some new feature to the software I didnt know was there.
If you have any questions, feel free to ask!
1)normal low position, 2)showing mount ball, 3) high position, 4) high position side view