When I originally purchased my Zumo 550 I used the RAM mount supplied with the GPS. I didn't really like the location and the look mounted on the handlebar. I bought the HD Fariring mount and did the install. Overall, I love it. The location is good, the eye point is great for my height (6'1") and the vibration is greatly reduced. The only downside is that at my height it blocks a small portion of the fuel guage but I don't find it to be a problem. JMHO.
I bought the HD 3 pouch windshield bag and I had to cut the left pouch off to make it mount next to the GPS Mount and look uniform. Looks good and is very effective.