I was driven to very high current / power amps for my love of electrostatic / planar speakers. Hence Pass designed amps. When I finally moved to traditional speakers I felt the possibilities opened up.
Higher quality solid state amps generally increase detail and slam… making them more dynamic. High quality tube equipment will increase detail and flesh out the midrange and bass… giving great nuance to these frequencies and bringing a better connection to the emotional content. Of course there is a lot of variability to what you get from either camp.
My most recent switch was from a Pass x350 to an Audio Research 160s (which I have operating in triode mode, so 75wpc). My speaker efficiency are 90db. While the slam dropped and up front, highlighted details… the change was jaw dropping. The bass and midrange opened up being completely fleshed out (bloom). The emotional connection… less analytical, so much more musical that any tendency to listening to the system instead of the music completely disappeared. I now listen to my system at least twice as much as I used to and have a hard pulling myself away.
While my comments on the solid state may sound attractive, there was no way that amp was going back in my system, ever. I got back tenfold for what I lost. To me the list for up front detail and slam came from college and led me to miss what was really important my system.