I tried this for a bit, and elements of it did create some good play and action. I did find that my flanks were badly exposed however, and conceded quite a few goals in that regard. I used Leeds United with it as we are currently blessed with quite a few good central players and attacking mids.
Havent tried it in any leagues but the Danish but there it works like a charm with a mid-table team. I use defenders with high heading and positioning abilities. Do you have any ideas to make it less vulnerable from crosses and still keeping the libero?