[KevWind]

The only possible advantage I can see might be two less conversions, as to whether that would translate into a noticeable difference in delay I would doubt it .

I use AES digital I/O for my Bricasti M7 Stereo Reverb FX unit into Avid OMNI interface. I do this mainly to keep my 4 analog inputs available for 2 mics and my stereo analog compressor.

I am no expert but I would think that any advantage of using digital over analog input delay wise (if any) would depend on how automatic or manual delay compensation is handled in your specific DAW.

There is going to be some delay in digital FX processing no matter what type of input you are using. If that delay is noticeable depends on a number of other variables besides input format.
I am not sure where you are getting your reading info but I would suggest that as a blanket statement, that might only be true if your DAW does not have any kind manual delay compensation feature or method handling for hardware inserts.