I have all three but haven't ridden the Pro yet. I like both the B17 and the B17 Narrow, but between the two I prefer the Narrow, and I could tell a difference. I generally find narrower saddles to be more comfortable. We'll see about the Pro, but it's still pretty wide. I also have a Swallow that's ok, but I still prefer the B17 Narrow so far, probably because it's the narrowest of the bunch. That said, I like all of them.

B17 - 175mm wide
Team Pro - 160mm
Swallow - 153mm
B17 Narrow - 151mm