I also use a Mio one with a Garmin Edge 1000. No issues and works well. The Edge won't record data from the Mio until you put it in workout mode. Apparently, it doesn't start broadcasting in ANT+ mode until you do that. When I use it with my phone in bluetooth, once it's paired, the HRM data comes across whether it's in workout mode or not.

I'm with you. I hate the HRM chest straps and won't use them as a result.

J.