I have a Rooney 2XL and it recently terminated my puck of Mitchell's Wool Fat....with extreme prejudice!
Yes, it takes more product, but after a while, it is not really as much of a hog.
After using it a few more times, I think I've gotten the hang of it. It definitely requires slightly different technique from my other brushes but I'm loving it. Also I have to keep telling myself to use more soap and cream because I have way too many samples and I need to make room for more.