[particlewave]

I'm not going to debate with JR or his minions, but I will say that I am a mechanical engineer (MS, electrical - BS, manufacturing - BS), have researched the loads on the IMSB and have whole-heartedly decided on a roller bearing if and when I replace mine. A roller can handle the load far better than balls. To be fair, real world doesn't always match the numbers. JR has a ton of experience, but he is also very far from unbiased.
He will be in shortly to say the opposite due to loads, thrust or RPMs.

Food for thought: the trans input uses a roller bearing and it spins faster than the IMS. How often do we hear of those failing? Of course, loads are different.

Also, note the report posted on rennlist yesterday of a ceramic LNE IMS retrofit that failed after 30k miles.
Interesting read.