the peak-to-peak voltage of an AES signal is greater than that of an S/PDIF signal. if it were a longer run, I think AES would be a better option. assuming a short run from the V3 > DAT deck, as Teddy said, it shouldn't make any difference.
one other thing to consider, is if you expect to have patchers. if you take the AES signal from the V3, you can give any patchers a signal from the coax output. I don't know if that's really a concern or not, but something to think about...