So I now have the ability from my 8 channel Ramsa WZ-AD96M single rack preamp to either use the optical ADAT output or the AES/EBU outputs into my 192 Digidesign I/O. I'm only recording at 44.1 and using an old Aardsync II wordclock as my master clock.

My question is - does it matter which I use? Which is better?

Bits is bits. As long as you are using the same word length with a good clock and good cables, nothing will be different. Optical, S/PDIF, or AES/EBU.

AES/EBU has an advantage over S/PDIF for long distances because it's a balanced line.

Thanks Rick!