38F caught my eye, I've been pulling dough at 42F and getting decent layers but nothing like that tangy depth you described.

Flagstaff has some of the darkest skies in the lower 48, so I am not shocked a T3i pulled good data out there. But "cleaner stacks than all winter with the cooled cam" sounds less like old gear winning and more like you finally got a good night with no moon and low humidity. A $2,000 cooled camera does not magically fix bad seeing, and a 10 year old DSLR does not magically beat thermal noise on a warm July night. What you probably proved is that sky conditions and practice matter way more than the box bolted to your scope, which most of us already knew. Go shoot the same target from the same lot in August with both rigs on the same night and then tell me which one wins. Until then this is just a good night with a cheap camera, not some big truth about gear.