Should be about the same. All these high power pentode tube amps were meant to be distortion generators so as to give them mellow character while being able to power most speaker loads. This is the classic kind of amp TAS reviewers (esp HP) went gaga over. The names roll off the tongue: VTL, CJ, Audio Research, Jadis, Line Magnetics, Mesa Boogie, Cary, Carver, Manley, and Convergent Audio Technology. Anything putting out over 200 WPC into 8 ohms and costing less than $10k was considered a bargain. I sincerely doubt even one of them could attain a SINAD over 60 which is something even my $160 Behringer A500 can handily surpass.
I made the plunge into tubes in the mid-late 80s in a smaller way, buying a CJ MV 50 to power my LS3/5as at the time. For a while I enjoyed it, but I began to notice it overlaid everything with a kind of honey like glaze while blurring details. In short, it made everything sound homogenized and sweeter than live which to me is the very definition of a colored component. I found my Hafler DH 200 was actually far more transparent. So eventually I traded in the CJ and haven't looked back since. Generally, I think, people who want their music to sound a certain way (and I literally mean all their music) might find a tube amp appealing. So if you're the kind of guy who wants Johnny Rotten to sound like Tony Bennett, Keith Richards to sound like Chet Atkins, Stravinsky to sound like Brahms, and Wendy O Williams to sound like Linda Ronstadt, then tubes may just be for you.