My Magicshine puts out way more light than the MR16 overvolted to 14.4 that I used to have. Like, night and day difference.

As far as convenience, the battery costs me about 3 minutes a week to pull the battery off, plug it in at night, then put it back in the morning once a week. I bet if I figured out how long it would take to build the wheel and do the conversion to dyno, the payback time would easily be in the years.