Nevermind! I just spent some quality time with the AG500SC and I think it does everything I need. The PJ M500 gives me too many opportunities to screw up the EQ. On top of that, I was able to finagle a deal to get one for just a little bit more than a GK 1001RBII, so I'm a pretty happy camper. I also tried out some Bergantino cabs. There was a used 1x15 that I liked but I was not in love with the 322 or the 2x12/1x12 combimation that makes up a 322. Much too modern sounding for this old dude. Based on that I'll end up with the Aggie GS115 and GS210 cabs with the GS112 for practice or a spare cab. Who knows, maybe the GS115 and GS112 will be enough that I won't care about the GS210. Thanks to all who helped with advice in my original thread.
FWIW, I think that the Bergantino HT115 is really a special cab, and I would not expect the Aguilar GS115 to sound just like the HT115. And if you like more of a vintage sound, then I would strongly suggest you check out the NV-series from Bergantino (if you haven't already). Tom.