Though there are quite a few posters that like the old VS gut, I'm very happy with the BT7 formula.
I read a little more on the formula change and now Babolat uses 7 thicker strands of gut instead of the previous 15 thinner strands. My only gripe is that I've had 3 VS gut jobs pop overnight in the last 3-4 months. I was never able to be sure why. But this hasn't happened in a while, though.
VS (in my case Team) / 4G is a sublime hybrid.
Dunlop F 3.0 Tour 18x20 (6gm lead and leather); I think.. VS Team @54 - Lux 4G @50 will work