For other people finding this post via Google…
Note the conflicting response by Condo in this other thread when asked which Sigma 105mm lens they are talking about:
In this thread they said “DG DN” which would refer to the newer ART lens. The linked response is the older lens. It’s not clear which lens they actually have, but considering by all reputable sources the newer ART lens appears to be the sharpest normal camera macro lens it is safe to guess they actually have the older one.
Not trying to flame Condo, just want to remove any confusion for others finding this post that returns pretty high up in a search.