This may just be me, and though I have never heard the new Jubilees in person to compare to, I have to say that every video recorded demo I have watched, they sound fantastic. Probably one of the best sounds I have heard and I don't pay too much attention to these demos, but those, they're different.
Thanks!
I too owned MC30s which I sold many, many years ago. I liked them enough but really didn't use them and, at the time, preferred having the cash (June 1988). I've reworked a few pair of MC30s and have done a few chassis replacements on other McIntosh amps, but this was the first MC30 with a chassis replacement. I have a pair of MC40s in the que for the same.
Take the bottom cover off, the factory units are dull, bare metal finish on the underside with ink stamped codes. The new make are mirror like on the underside and no codes.
I've noticed, over the years, that a lot of folk migrate back to a pair of LS. They're big, but not too big, with a great presentation, whether tweaked or not.