Garmin customer service is excellent. Their product, thats a different matter. I'm already on my third Garmin 520.
So the thing with Garmin is that it takes about 2 years for the firmware to stabilize. Once that happens you're basically good. During the first ~18 mo, every other update with break something else. My 510 had some issues (always firmware related) but it's been like a rock ever since Garmin moved on to the 520 for development.