I have the Garmin 550 and have been happy with everything except the blasted suction cup window mount. I got tired of it falling off and went out and got the dashboard beanbag mount- works great. The 550 has bluetooth with a mic that can be clipped to clothing or attached somewhere on the dash (as I have it now). Gives streets by name unless you switch languages (the English hottie will only tell you to "turn left" but no street name).
As a word of caution regarding thefts. Leaving the rig in plain view is a bad idea and is getting worse. Even if you just walk away for a few minutes. I've investigated numerous burglaries here in Houston where folks have left the unit in the window then returned only to find their window smashed and GPS gone. This is another reason why the beanbag/dash mount makes sense. The resident "turd" who breaks into your ride will look for the suction cup marks left on the windshield even if you've removed the unit and hid it somewhere. Obviously the dash mount leaves no traces behind.
George, Cary, & Roxie the English Bulldog..''99 silver #1897