Only if your DAT has better converters than your sound card. If you have a good card (USB, or whatever), then no.
I transfer tapes (and most other sources) with a CDR-W33, Sony's pro CD recorder that has SBM and also a limiter and eq. Good sound, and big advantage convenience-wize since it's in my stereo rack with the cassette deck. I can then pop the discs in the computer and do whatever else I might want with them (e.g., noise reduction). But I might stop this method since recently upgrading to 24/96 capability on my computer.