Sounds like it's an old 2-channel and it's probably REV F, which means it's darker (muddier) than REV G Rectos. REV means 'Revision' of the circuitry board. The older pre500 were REV C and REV D. They were sharper sounding, brighter sounding and more notably, shred machines. It was George Lynch's 'secret weapon'.
The following REV was F, more dark and muddy/bassy. Very low in treble and presence and one of my favorite amps. REV G (the latest revision) are more balanced yet fizzy, yet more refined. Also a great sounding revision, just have to try and eq out the fizz.
To fix your problem, don't use the BBE, that basically scoops the mids and adds bass. Treble boost or a nice EQ system will help you with your problem.
You are definitely a lot better off than your old system, though you will miss all the effects the POD Xt provides. The recto will be more full and punchy (tube power). Though I hear the AVT is loaded with a 12AX7 and sounds decent for a hybrid.
What are the serial numbers on your recto? I might be able to tell you more what you have.
Oh, as far as tube life, it's hard to say if they need changing. If they been played a lot, they'll last about a 1 year. The REV F are dark amps to begin with. But exhausted tubes will make the amp sound totally lifeless... so that might be a problem too. Can you ask the guy who you bought it from about the tubes?
Rectos are great amps!
-- however, correct me if I'm wrong, but I think most of those bands you mentioned play Mesa Boogie Mark IV.