I backed the original indiegogo campaign and have 'signed' 9 rounds with it so far this year (user name 'frosty' if anyone is interested) and here are my thoughts:
1. Tagging takes longer than you might think to get used to. My first round ended up being something like a 68 (instead of 81!) because I missed so many shots. My last few rounds, by comparison have only been off by 2-3 strokes and pretty much all of those were just putts.
2. Proper round review is very important. My current long drive is 398yards because I didn't notice I'd missed tagging an approach shot (but had double tagged a chip) so total score was correct but distance, not so much. Once you 'sign' a round it is set in stone, apparently, so I ended up creating a 'new' driver to get those outliers out of my averages. That being said, I can now review and sign a round in just a few minutes and the interface is reasonably snappy (unlike its original incarnation which was terrible).
3. You really have to charge the thing every round. The product literature seemed to indicate you could play more than one round on a charge but every time I've played (starting with a full battery) and downloaded later that day the battery level has been listed as 'low' on the uploader screen.
4. Once you have the raw data you can continue going back and adding stats. The shot-maps that people were posting screenshots of were not available on launch day, but were added as a new feature later.