Bookshelf speakers with a tube amp?

Hi. 
I just sold my Klipsch Fortes. I have a Cary Rocket 88 (40 WPC). I’m now pairing it with Boston RC8 speakers (25-125 W). So far, I’m pleased, because I have a wonderful SVS Micro 3000 sub. (500 W)
  I have an option to grab Solid State amps: Marantz 2226 B (26 WPC) or a Pioneer Sx-7 (60 WPC)… I wonder about whether I should see or HEAR enough credible difference, either gained or lost, if I switch to solid state from the Cary. I was surprised at what I heard in clarity and midrange in these little Thrift Store Boston RC8’s. But my question lies in the tube distortion sound, vs. solid state power. I think I’ve heard it said that tube watt ratings, though lower, play with power ABOVE rated WPC. Right now, I like the Triode mode in the Cary, at (26 WPC)… better sound than UL, yet less power. Klipsch Forte are 95 db sensitivity, really MADE for tube one would imagine, yet I guess if the Bostons play without distortion (off the Cary), then is it more of a strain on the Cary to play it closer to full blast… to run bookshelf speakers needing more power?

what thoughts are appreciated…