LOTS of good thoughts here...
Corbin -- yeah yeah... you're probably right about the 188. I owned a great one, sold it,

and then could have bought another great one last summer, and didn't.

I only sold mine because I thought it was more work than I wanted to make it sound big. Little did I know, I preferred that sound, even if it took a lot more work. Best ergonomics of any horn I've owned.
Mark -- I'd love to be an Alex 163 player, but I'm concerned that I'd have the same difficulty I had with my Rudy Meinl; it's a tuba that demands to be played, and rewards you for playing it. Do you find (or not find) that a little time away from the Alex makes a difference in getting back at it? I've heard they are a little unforgiving for irregular playing.
Alex -- I owned a 1291 for almost 5 years. In fact, that was the first "big" tuba purchase I made... and the first "big" sale that set me off in this tuba swapping spiral.

I liked it a lot, and it served me well. It played easily and sounded good on recordings. I kind of wrote it off after trying (and owning) some other things. Maybe I should give it another listen. It was a comfortable tuba to hold and play, and easy to pick up after a few days off -- that might come in handy right now. Plus, I can't hide that I'm a Miraphone guy. Thanks for the reminder.