I have been playing my new SCSTs for about a month now. I am using a PrimaLuna Prologue Premium integrated running EL-34s, about 35 watts. The synergy is very good and the speakers are very easy to drive.
I have noticed that they have changed over this time. The bass has increased in depth and articulation and the mids are so good that I find the hair on my arms and neck standing up. The highs are really sweet and I was running some NOS Mazda Ciftes in the preamp section, but found I liked the NOS Mullards instead.
You will enjoy your new speakers and they really sing with tubes.