In the replica market there has been a movement to water cooling. Obviously it adds reliability and power. But it also saves build costs. Suby is much cheaper than a power equivalent Type 4 or even Type 1. Can't imagine how expensive a late 90s air/oil cooled 911 flat 6 would be now. I would love to build a nice Type 4 with the 44 Dellortos I've been saving for 25 years but in reality I'll probably submit to the reliability and economy of the Suby EJ.
I actually love the idea of a watercooled flat 6 in a Super Coupe. Its the ultimate replica progression. Its more blasphemy. And we clown car owners love blasphemy. Emory would never do it. He would spend 4 times as much chopping 2 cylinders off a 911 oil cooled engine to make 200 hp. The clown car builder justs takes a 300 hp modern water cooled flat 6 and crams it into a 2000 lb Super Coupe. I love it. God bless the clown car.