I just picked mine up today. I previously owned a 705 edge when they first came out. Nice unit but I didn't need the mapping. I've been without a GPS for a couple of years so the 510 was a no brainier for me. My wife will love the live tracking feature as I do a lot of loooong rides. Here's one of the best reviews I've read on the 510.
http://www.dcrainmaker.com/2013/01/g...th-review.html