Yeah, blame the boat. My wife skied behind our 197 and then the TXi this weekend. She is just learning to run the course at 26 mph. She couldn't tell a difference and I couldn't visibly see any change. I then pulled a M6 skier, 32 mph from 28 up through 38 off. He can't feel any difference in my wake vs. his Txi.
I'll admit that the wake at 15 and 22 is harder, but to say it caused an OTF for some M4 skiers is nothing more than an excuse.