I've installed the "Do it Best" bearing on my XT12i. While this is a new mod for me and I can't answer regarding long-term use the thickness was perfect, at least for my encoder. It does make the azimuth too easy and some form of braking is needed in addition to the lazy susan bearing. Right now I'm experimenting with center bolt and I'll go into more detail if that works out. I know leaving the teflon pads installed will add considerable friction to the movement so perhaps leaving one or two might be the right answer.

As far as the lazy susan bearing developing flat spots over time; I'm not sweating that. The bearing, once placed is easy and cheap enough to replace.