I finally got a second back-up amp just in case my STM 900 blows up for no apparent reason. I went with the Aguilar TH 350. No effects loop, aux input, headphone out and only one speakon output. About the size of a cigar box but not as heavy. I've taken it out into the real world like 4 times now and gotten more aware of how to set it. It's different than the Benz; not quite as warm and more articulate. But it's very good IMHO. The controls are intuitive and powerful. You can warm it up nicely between the drive, gain and master controls and the sweepable mids are a plus. Unlike the Benz, all of the tone controls are active (I think) so it's a different set up, i.e. put everything @ noon and go from there.
I'm using it with two Aggie SL 112s and it's plenty loud enough. I have no way to back this up but I suspect the TH350 is equal to the STM 600 power wise and ditto for the TH 500 compared to the STM 900. Couldn't say whether I like one better than the other at this point, either unit is great and a joy to pack up at the end of the night. I definitely do not miss 40 lbs worth of F1X/power amp, rack case. The 25 lb cabinets are pretty cool too. BTW, if you ever want to buy any Aguilar stuff, I highly recommend Texas Guitar Ranch through E-Bay. Free shipping, same price as everyone else but they throw in real Aguilar cases/covers for free. I would have been too much of a cheapskate to buy the covers for these cabs but I'm glad I have them.
There's an Aguilar demo video for this amp on YouTube that I found rather amusing. It features Wooten's bass player playing through this little Aggie mini stack. "I love this rig, sounds great!" he says. Mr. Aguialr asks: "So can you tell us how you use the fantastic tone shaping controls in your playing?" The amp is set completely flat with the drive control off. "Well, when I'm going to solo, maybe I boost the mids up a little to cut through more", then he proceeds to boost the mids with the controls on his (active) bass. Poor Mr. Aguialr!!
There are two kinds of music, the good kind and the other kind. I like both.