msandler:actually Mech, I didn't say that. Rephrase: Failures left unaddressed by a good H-valve setup are few.
Sorry, I didn't mean to infer I quoted you.
I see your reasoning for using an H or Y valve, but just think that, given the need, I would much rather have manifolded doubles. If the need is not present (most all rec diving IMO), then I would not bother with one.
MD