I use a 990/7700 combo (300 watts into 4 ohms) to drive my M80's and 99% of the time it's plenty. Although there are times I'd like to try maybe a Classe or Mac mono block at 4 or 500 watts just to see. At anything other than INSANE listening levels the Outlaws are fine for what they are. I do find that the M80's tend to open up a bit more and get a much warmer richer sound though at mid to moderate levels. Which makes me think that even the 7700 might be "just" enough to drive them well. I truly believe that they want some serious power behind them to show off their capabilities, even at lower volumes. Also have an EP600. The room they are in is roughly 14,000 sqf and it gets filled up fine. You may want to think about a sub too depending on your listening pleasures.
So will the 2150 work? Yes, but I'm a believer in buying as much power as you can afford within reason. Besides, you never know when you might want it!
