I'm on a pretty strong downturn at the moment. I blame the idea that playing with "rhythm" makes a positive difference. I switched back to 14.1 a month or two back and attempted to work in rhythm with a more fluid stroke. It's absolutely killed my consistency, and produced a slight inside out chicken wing.
Thankfully, when I looked for the problem I was able to spot it. I've unfortunately engrained it slightly, so I'm having a hard time reverting back.
Fortunately the problem is really only bad when I'm playing 14.1 solo. It hasn't effected my competitive game all that much, but it's there enough for me to tell. Everyone else thinks I'm just being lazy and not giving it 100%