Just picked up my car from IS Garage.
I can't tell any difference in car feel compared to before the bearings change.
Maybe the idle is slightly smoother now, but that's likely due to new motor mounts.
See condition of my old bearings here:
http://www.m3post.com/forums/showpos...&postcount=481
To me they don't look too terrible, but glad I did this for peace of mind anyway.