Have had the Zumo 550 since it came out. They have had to get some of the bugs out, but it's fantastic. On a bagger that has the auxiliary input, you can listen to music from the mp3, get route instructions from the gps and not have to go back and forth to AUX and Radio. If you have intercom and CB, they are on seperate circuits and donot interfere with the Zumo. This means you keep the radio set on AUX and that's it. You have the luxury of GPS, MP3, intercom, and CB all at the same time. The Bluetooth can heard, but you can't respond without another mic connection. Haven't wanted to be bothered by a phone call so haven't looked into that. Just went through a couple of downpours on my way to Sturgis and had no problems with the Zumo getting wet.
Problems;
For the car mount, the round plate needs to be sanded and a much better double face tape used to keep it attached to the dash. I finally used a silicone to keep it attached. The suction cup also lets go, with or without the Zumo on it.
There is a magnetic and rubber connector cover for the bike mount. This has a flexible rubber connection to the mount so when the Garmin is not on the bike, you can flip up the cover to protect the connectors. After a short time the flexible rubber breaks and you can lose the magnetic cover. Garmin has recently come out with a redesigned replacement that is not supposed to deteriorate. They replaced mine at no charge. They have a super customer service staff.
Lastly, I have had a gliche in the show map screen. For some reason it comes up with a map of South America after you go to the turn by turn printed route screen. They are working on that one.
Framemaker, 06 SEULTRA, Crimson