The answer would depend on how far away you sit from the speakers, and how loud you listen... but my guess is it would just make it at about 3 meters distance.  Anything less would be louder.

Two things will change.

Low volume performance will likely improve and the amps ability to make a speaker disappear makes it possible to near filed listen and have it sound like the speakers are 20 some feet away.  

Those two factors, plus the speakers have powered subs... probably work rather well at normal volumes.

Steve

Steve said something that I have found to be so very true in the few days and few dozen hours I have used my UFO2 on a decent size pair of 3-way Sonus Faber towers (rated at a lower 89 dB sensitivity...and these speakers love power).

The low volume performance is exceptional.

I have a 200 watt per channel McIntosh SS amp, and it sounds good, especially when turned up.

I added a MC275 (75 watt per channel tube), and noticed the bass was deeper and better controlled, especially at low volumes.  Overall, just more alive and engaging than the SS amp.

The Decware has continued this trend further still.  Phenomenal bass, especially at low volume levels (as well as the overall sound) - but it does not sound small, the opposite, it sounds big at low volumes!