Some studies have shown that there is less jitter when using electrical digital transfers compared to optical. The thing is... when you downsample, it has nothing much to do with digital transfer protocols like AES/EBU or spdif, but more with the downsampling algorithm available to you, usually via software. There is also the subject of dither, which adds very low level noise to minimize the artifacts of quantizing error during downsampling.
Personally, I am not fond of A/D/A transfers, but I somehow think that if you are using top notch A/D/A converters when 'downsampling' via analog, it should not be that much apparent as long as you use the highest bit rates available (usually 24-bit) and you keep A/D/A transfers to a bare minimum, preferably during the mastering phase. I prefer to downsample via software, and I have been using r8brain which has proven to be quite transparent compared to other algorithms, although I really haven't tried any newer ones to date.
