I came to this opening via research on early 20th century chess theory. Naturally it is common enough in the modern game that not many players care much about its utility.
However, I found these two games that make it rather interesting:
It seems that in both games the White's Black Square Bishop holds a key to the position. It also would seem that Black has no clear way of capturing that Bishop once it is on g5 without losing positional advantage of Black 0-0. In my opinion Black takes unnecessary risk allowing White to play Bg5.
Please leave me some comments with regards to this opening.