If you have read the Soundstage review of the topaz, you'll find that Mickelson reviewed them on a pair of WP7's and found they had plenty of power. In comparison to the Lamm ML2:
" The amps' power output seems about equal, with perhaps the Wyetech amp playing more loudly before it lets you know that it has reached its limit."
The similarities and differences are laid out between the two in the review (the $9,800 Topaz and the $30,000 ML2).
Personally I have found the grainless purity combined with the power and extension to be unbeatable. I have had amps that have sounded slightly more powerful in the bottom end (60 w push-pull tube mono's) and other SET's that have had a sweeter tone but I have found the Topaz to be amazingly natural and real sounding. I've had OTL's too. They have their strengths but are not as natural sounding.
FYI my taste in music spans the entire spectrum. Jazz, Folk, Blues, Classical, Rock, Metal. The Topaz was the only amp that did all of these well. And I owned the other three amps while I had the Topaz so the comparisons were done over several months of ownership, not an evening of listening.