I have used C/Y lenses on my T1i and 60D with no problems. I read of others using them on the original 5D with no problems. I have no first hand information about C/Y on FF digital bodies.
Most of my comments are about lenses. I had two really exceptional C/Y lenses. The first was marketed by Vivitar - the 28-105mm zoom. I think it was actually made by Tokina and was f/3.5-4.5. I donated that one to a local high-school with a bunch of other C/Y bodies and glass. The other really good C/Y lens, which I still have, is the Vivitar 70-210 f/3.5. I got this lens for $99 on e-bay. The serial number starts with 37, so I know it is a Tokina product. This really is a top-flight lens in every respect. IQ and build are superb. It is smaller, but heavier, than the EF-s 18-135 and f/3.5 at 210mm is pretty darn fast!
One other lens that is worth buying is the Yashica 135mm f/2.8 MLc. All around winner, in my book.
Yashica marketed a lot of mediocre lenses. Most of them were designated DSB or YUS, in the model name. The good stuff was designated ML (multi-layer), MC (multi-coat) or MLc. The 'c' is for compact. These are completely different lenses, with different coatings, than the DSB/YUS stuff. There is a lot of DSB/YUS stuff out there, and it is appropriately inexpensive.
The good stuff is harder to find and more expensive. I find that most people selling this stuff on e-bay don't even know what they have. It was handed down from grandpa, or found in aunt Mable's place after she left this world. Some really good bargains are out there, if you keep your eyes open.