Your comments on the Blue Sensor Mirror are the exact same experience as I've had. I'm pretty convinced it's one of the best lenses ever. I pretty much never remove it unless I'm actually riding into the sun. I'll second their proness to scratching, but I worry less about it as I've only had to replace mine once in 3 seasons and the replacements aren't completely unreasonably priced.
Are you riding your I/OX with a helmet? Only reason I ask is with my I/O I had to get the extender which I didn't find to be a big deal, but I think I would prefer the clips for the ease of putting them on or taking them off.