My point is that it's irrelevant at this point, as those machines do not yet exist. The existing experimental setups and theoretical models are most closely related to boolean circuits (vs a Turning machine or a RAM machine or lambda calculus or whatever is your favourite computation model). But you can still show gains on some sets of problems (like integer factorisation).

Yes, quantum fuses the memory with the CPU. Taking the data out of your processing unity is a classical copy and will cause decoherence.