I've got two of these kinds of setups and I don't see myself ever going back. One with a rack power amp into a couple of 212s and the other with a Quilter MicroBlock and 112. I have a Theta in one chain and it's a great sounding pedal. Probably my second favorite preamp pedal next to the Tight Metal, but I've yet to try a Ceres (which also has a clean channel). The Theta isn't a grindy type of 6505 sound like I love, however the active EQ and mid sweep allows you to dial in a lot of tones. It can still get really gnarly. One quirk the Theta has, if you plan to use the preamp section as a clean channel, it won't be able to function as a built in boost for the gain channels. I use an external boost with mine, but it's something to consider.