I'm not sure that power is a problem, I think the VP100 and VP150 are fine in that category. I'm not as technical when it comes to speaker design, but it has to have something to do with the design of the cabinet and/or the drivers specs. I thought the VP150 used the same type drivers as found in the 60's for the tweeters/woofers?

To me it is very obvious when I run the Test Tones, the pink noise sounds different coming from the 60's versus the 150 versus the Qs8's.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85