I have tried 95 for some games, and just settled on 99.
For most of the penalties that do get called, I went from default settings and up in increments of 5, playing many games. I found a pretty good balance for all the penalties that do get called, though (in my slider thread).
The two penalties that just seem most random is clipping and holding from my testing. Slowly adjusted all of these up as I played games. For clipping, 85 seems like the sweet spot, but then again it can be just like holding. I got holding at 99 and I DO still see a holding call in a game or even multiples in a single game, sometimes every other game, but not as often as I'd like to see. I still see them though, so it's okay I guess. I really did spend a good bit of time adjusting penalties, since I was finished with my gameplay sliders so soon, and I believe I found an okay medium.