Power requirement for tube Amp to drive Summit

I've found that using a tube pre (BAT VK31SE) with high quality high power SS amps (ARAGON Palladiums 600wpc@4 first 140w class A) gives me the warmth of tubes with the dynamic capabilities of SS with my Summits. When I got my BAT pre I also had the VK55 which made the Summits sound small and overworked. That's when I went to the opposite extreme on the amplification side and the Summits had the sound of the large, effortless speaker that they are. I've experimented with several amps and find that anything under 200 wpc doesn't do justice to the Summits in a good sized room.