slag the stock bushings....LOL autocorrect.Hi Rich,
There is absolutely more harshness with the bearing RTABs, but it's not tooooo bad, better than poly. And it's mostly over square edges and reflectors or lane markers. The trade off is, of course, rock solid drive, no squishiness or squirming side to side (deflection/toe change). there's also no noise like there can be with poly. Theoretically, bearing rtabs will wear your tires less due to less toe change I believe.
That said, if you're willing to DIY (and do so in a way that preserves the alignment or pay for an alignment each time), then you could also just keep replacing the RTABs with stock (Oe/lemforder) every 30k or whatever. Stock is massively underrated.
Very few people can remember or ever knew what a brand new e46 m3 felt like. They buy one with old, worn bushings then slate the stock bushings, and go straight to hardcore stuff.
As far as spherical rtabs, I like my SDW (can get them at fcpeuro now!), but CMP, dinan, fall line, tms are all good.