Before I got serious about restoring my pre-amp and studying the SM I would have said that it doesn't matter.
But then I found that with my pre-amp the input buffer for CD was seriously overbuilt with all discrete components. And for some reason the tape-3 input buffer is the 2nd best, with 2x dual-channel op-amps and a far more complex design than the rest of the inputs. All the rest of the input buffers are identical, with a simple single dual-channel op-amp. (Not counting the phono input/buffer)
The point being that it may pay to take a close look at the service manual and schematics for your pre-amp(s). You may find that all of the input buffers are the same, or you might find that 1 or 2 are a bit better.
Cheers,
James