Herman,
Ya gotta be a pretty inept tech to make a Conshelf breathe bad! There really isn't much to 'em. Simple, tough, reliable. As for the Aquarius, what parts? It only has one moving part and about all there is to replace are a few O-rings. I'm up to my eyeballs in Aquarius regs and every one of them is ready to dive. They make great backup regs to save a day's diving if your primary decides to pack it in. Their only shortcoming, as far as I can see, is the shortage of LP ports. Yeah, they're unbalanced piston regs but that doesn't bother me. They still breathe well and they are extremely dependable. Heck, you know all this, Herman. You have a few of them yourself.
I agree for DIYers like us, I was looking at it from the perspective of a "take it to the shop" diver.
Remember I make the parts for a lot of regs so "no parts" is not really a problem, just fire up the lathe.....and a friend of ours has me working on more.