It's all about system synergy. I replaced several highly regarded tube amps with SS amps and boy I can't believe what I had been missing:-) Really!
Now, I had the same thing happen in reverse with different speakers. It is all about the speaker/amp synergy folks. This is not a tube/SS thing IMHO.
I do love tube amps however and will always keep my tube preamp no matter what amp/speaker combo I have.