You are spot on. The cost is huge to make that upgrade, and the savings is weight (of little value to us) and power consumption (would be beneficial but so far not at the cost).
I'd have to agree with your choices. You guys are in a completely different game than most of us mobile guys. In my case, it's good to be able to run everything off a single circuit. I'm also driving a cargo van instead of a tractor trailer so weight means something to me where it means relatively nothing to you guys. I'm assuming you guys are also doing a fair number of outdoor events. I can tell you, as a former performer, the heat off those cans was really nice when we were doing an outdoor event in the cold. My one question, do you ever run into situations where you can't wheel everything in (stairs) or where there's no loading dock? I'd hate to think about trying to hump some of those big cabinets up a 45 degree inclined ramp into the trailer.