You've already seen how useful room correction is for your set-up. More advanced correction will clean up the sound even more.

If you are happy with the volume of your system today, and you are not hearing mids and highs breaking up, then I'd say you don't need more power. You have about 20 dB of headroom in your system assuming a nominal listening level of 82 dB at 8 feet MLP.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated