For the 3D framepacked 23.976fps issue: It seams that it also depends on your TV whether or not you will notice the microstutter. Some TV's are able to compensate it somehow, so you wouldn't ever notice any stutters at all. (This has been already discussed a long time ago, maybe you can search it over). This is the case with my Samsung H6400 (active 3D) TV as well. While others, with other TV's, still perceiving and reporting the issue.
Tho' while the "regular" 23.976fps->24Hz bug was still present (with the ver early firmwares on the beginning), with all kind of 23.976fps videos, i still had perceived 100% sure the mucrostutters on this same TV.