Grumps: I've owned several of both over the years - still have two TT's. The Conns are believed to have a huge voice - and the ones I owned (and played) did have a lot of oomph.
But my Bueschers all have had better scales.
Tone-wise, it is a toss-up, I believe (mainly because the player has such an influence over that issue). I recently played a couple of gigs with George Probert (of the Firehouse Five plus Two fame) and I don't know ANYONE who has a bigger sound than George. He plays an old Conn. We did well together. DAVE