No, I'm not having any oil blowby problems (knock on wood), otherwise I would have put the catch can at the front to stop oil from soaking the air filter instead. In fact, the oil level hasn't moved on the dipstick since I put Mobil 1 in the pan 3700 miles ago so I'd say my stroker's doing fine. It goes like a bat in hell.
The inside of my intake manifold looks like the Ace of Spades (don't they all?) so I only did the oil catch can mod to prevent it from getting even worse. You'll get that with any healthy running 4.0.
I've been running the catch can for about two months. I haven't drained it yet but I doubt there'll be more than a thimble full of oil in it. My "drain plug" is very easy to reach where I have the can mounted.