If you don't mind, please explain what you mean by "harmonic integrity"? I've done extensive auditions with tube amps from the likes of VTL, BAT, MAC, Rogue and Belles and they all exhibited midrange harmonic "bloom" to some degree or another, and I believe that's what gives them their unique character. If not so, why bother with the low power, the expense, the heat, and the cost of tube replacement. 9 out of ten "tubies" I've spoken with do so for the ability to "tune" their system by tube rolling...utilizing the distinct harmonic distortion character of different tubes to their advantage.
To me, harmonic integrity is the ability to integrate the musical fundamental with the harmonics of the instrument, a sort of continuousness of reproduction that, all things being equal, SS doesn't do as well IMO. Having heard amps by CJ, ARC, VTL and McIntosh and compared them to SS amps by PS Audio, Carver, Spectral and a few others I find that the SS amps are less engaging and subjectively pleasurable.
Do the two topologies sound different, yes, that is the entire point. Do I feel that modern SS and Tubes designs are converging on a "standard" sound, yes I do! Simply listen to an older CJ or ARC amp and compare them to an equivalent modern version. My experience is that they are starting to sound far less tubey, in the old warm, syrupy sense, and more neutral, extended and fast w/o the potential hardness of SS.
Regarding tube rolling to tune the sound, it is a definite benefit IMO. I would think that if SS owners could easily change out their transistors and/or mosfets they to would partake of the rolling habit also. Or should we assume that all SS devices sound identical in the same circuit?
Definitely tube amps require more user input in terms of tubes and tube replacement, biasing, heat and such but power is no longer a limiting factor. Keep in mind that the VTL Siegfried is 800 WPC @< 1.5% THD, I couldn't imagine needing more. The Pass Labs X1000.5 is 1000 WPC @ 1% THD and is also an exceptional amplifier I am sure (haven't actually heard either yet.)
YMMV