I haven't really investigated the grip profiles and how it compairs to the OT T-tracks. I don't trust the PropShop saber much as a reference. I saw it at SW celebration this weekend, but it was displayed in a dark exhibit, and it was hard making out the details. I DID hold my own version which I brought with me next to it, which drove the booth people CRAZY! Haha, they were impressed by my own Graflex based version.
Anyway, when I'm back, I will focus on the profile shape and form an opinion.
My feeling about the material is that it most probably is hard plastic, because rubber profile is much harder to produce accurate and straight, and is harder to mount straight as well. Since some stunt sabers were fitted with textile covered foam rubber grips, that might have created the confusion. Or it's just a slip of the tongue. About offering a newly profiled T-track: I don't know yet. The investment is high, and I'm unsure if this one saber will pay it back
Modifying my current track might be an option. I will let you know in a few weeks.
Roy