Maybe it's all in my head, but I've always found that the more power I can feed the speakers, the better they sound.
For example:
I'm sure if I had the m80s with a Pioneer Elite at 90db and compared that to running them through a power amp with 300w a channel, still keeping the volume at 90db, it would sound better to me.
Maybe I'm just used to running old speakers with old amps so the amp makes a much bigger difference to me.
I mean, it would be nice to not have to buy a separate power amp, so maybe I'll try it out first