I have Levinson 33h's on Thiel 7.2's. Their only limitations seems to be the current coming out of the Wall!!!!
it is a matter of degrees. the 33H's have plenty of punch and slam......especially if you wire them for 220 volt operation.........but........when i switched from the 33H's to the 33's......there was much more control and lack of congestion on the musical peaks (with my Wilson WP6's).
so my conclusion was that with speakers that can take advantage of mega-current (such as the WP6, Theil 7.2's, and Revel Salons) more is better.
keep in mind that getting the refinement of the 33H's with more slam won't be cheap.......you may find there are trade-offs. then it becomes a matter of priorities. even though the 33H's are getting to be a little long in the tooth from a design standpoint......they continue to be one of those few 'very special' amplifiers.
To answer your first question, no. The 33H is somewhat underpowered compared to the Krell FPB600. I've auditioned a couple of systems with the 33H's including revel salons and b&w sig 800's. They sounded wonderful with the salons at moderate levels (90db peaks), but clipped horribly with the 800's at less than 105db peaks.