NO. Really, the more power, the better!
People "clip" speakers, most every time, due to "underpowering" the speakers with their amp/receivers!!!
The more power/control over your speaker drivers, the better! Trust me, 23 years experience professionally.
Your THX select speakers design/config, however, is better suited to "smaller rooms", and/or room situations where you sit "closer to the speakers" in proximity vs. the room boundaries/ceiling, etc! Otherwise, you need much more attention, critically, to room acoustics.
It's all a "balance".