I'm narrowing down the amp search, ...I'm trying to decide betwen keeping my Mesa Mark IV and picking up a used Bad Cat Cub2 ( am I a 2 amp guy? ) or ditching it all and picking up a Rt66...here's my question ( although feel free to chime in on the amp quest itself...) do I go with the Zbest 2x12 or go with an Avatar type 2x12...or keep my Mesa 1X12 Theil cab and use that? I've played the 66 through the Zbest and it sounded ( and looked) great but...do I need to break my back at my advance age? Experience with Avatars anyone? or another choice...?

No experience w/ the Avatar, but I owned a ZBest and I'm here to tell you that it's a heavy mofo. If you're going to buy one (and they DO sound freaking great, no question), you might want to hire somebody to carry it for you, too.

My little 212 cab is a Traynor. It's slightly smaller, with a metal grill protector. It's Birch Ply, and weighs about 2 lbs. less than every other 212 cab I could find. Sounds really good, too. I think it's either 40 or 41 lbs. Whereas the average seems to be 42 or 43 lbs.

Plus, it's a little smaller. I think it's a little more focused than some I've tried.

I'd also suggest checking out a 210 or 410 cab. 10s sound more detailed to me, than 12s.

I've found the Avatar cabs to be nice bang for the buck. A 2X12 will run around 50lbs.

Another cab maker to look at is www.earcandycabs.com I have one of their 1x12' cabs and it's wonderful. Sounds great and actually very compact. They also make a 2x12' that's quite nice.

I am personally a huge fan of Mesa cabs. My .02

Maybe pick up another Mesa 1x12. You would have more options. 2 cabs if you need more umph and 1 cab for really small stuff. I personally use 2 Rivera 1x12 cabs and love the portability and flexibility of this setup. Having 1 cab on the floor beefs up the low end while the top cab is mainly what you hear.