Update 1: GK BL600 + 410GLX. Really dug the head ... the cab left a bit to be desired--the low lows (drop-D) were a little flabby. I still think I'm a 15s kinda guy.
I'm checking out the Triad tonight (I know, I know ... but as a former Peavey 1516 lover, I have a soft spot for oddball cabs. Gotta try it). I'll be trying it with a GK 1001RB and an Ampeg SVT3pro. If I love it, I'll probably go with it and the BL600. Still, there seems to be some concern about the cab's efficiency, correct? I hear the thing just isn't all that loud?
Next up, that weird old Ampeg V6B. Something tells me, though, that its impracticality is going to be the decider there. After carrying a 60-pound dog up and down 2-3 flights of stairs per day for the last month (torn ACL ... poor guy), the idea of lugging non-Neo cabs is not too appealing. Which would eliminate the Triad, too, but at least it's a lot shorter.