Hi Eric,
A few comments: the M80's are very detailed and linear through the midrange and highs. They won't be kind or flattering to bright, aggressively recorded pop/rock CDs that have boosted (EQ'd) mids and sibilant vocals emphasized for playback on FM and over inferior portable gear.
In other words, be sure the source you are listening to is a nice, smooth, balanced recording. Like any great loudspeaker, the M80 will ruthlessly reveal problems in the source material, but with fine recordings, it sounds wonderful.
Cables shouldn't make any difference (as long as they're thick enough), and a couple of hours break-in are sufficient. The tonal balance of the M80 and M22 is very similar on good recordings. The M80 may sound a trifle more forward on some vocals but it has deep, profound, and well-balanced bass output, especially compared to the M22.
Ravi is correct: try running the M80s in stereo bypassing the digital processing section (if you can) of the Outlaw before you assess the M80's sound quality.
Regards,
