You know as well as I do if the carb wasn't working right in the first place, you can't use it as an example of MPG or performance.
PO on my car with a 307 in it had disabled the computer, and I was getting 10MPG becuase the carb was stuck on full rich, all the time. Probably near 20MPG if it was working right.
I'm sure it costs a lot to rebuild the CCC carb if you pay someone, however the MC solenoid almost never fails (probably because it was the first time they really tried something like that, so overbuilt it) and I would guarantee that is one expensive part. The TPS is the same idea as TBI or TPI, so that is no more a problem than injection.
Everything besides the primaries on these carbs is just like a "stanard" Q-jet, so a rebuild is pretty much just as straight forward. New gaskets, clean it out inside, re-bush the primary throttle shaft perhaps, check TPS operation, and call it good.
Chips are as worthless for CCC as they are for TBI/TPI, and if you pay someone to burn a "custom" chip for TBI or TPI, you will pay the same amount of money. But for cruise, you can adjust quite a few things on those carbs to feed a bigger engine. You can open the solenoid up farther, you can get "jets" with bigger orifices, bigger primary needles IIRC, and other stuff that isn't even tricking the computer...you make mechanical changes that increase the amount of fuel delivered, and that keeps the computer rom havig to try and richen the mix all the time.
You are right, it's a fairly primitive system, but in one form or another it lasted until 1990, and the '88-90 setups were just as "smart" as TBI/TPI.
For all that work on one of these trucks though, I would swap to TBI first. On vehicles that didn't come with stock injection, the CCC typically needs to be worked with. But if you can swap injection ito a vehicle as easily as you can into these trucks, I have to agree that it's a better choice. Again, depends on what you do. I guess there is something to be said about having an induction system that flows 750 or 800CFM, and has no computer input at WOT if you are mud running.