I have a PowerTap G3 (will probably be selling it soon to), it broadcasts on ant+ and bluetooth, mostly survived multiple crashes (even sliced part of it off in a crash), SARIS is AWESOME when it comes to their warranty (they got it working fast and free of charge). It's very accurate and auto zeros when you coast, the only issue is it's built into your wheel making it hard to upgrade if you want to in the future.