Sounds more like "marketing" to me....
Spoke to BMR on the phone. They have internal flutes to help distribute grease more evenly. Whether it works or not is up to you to decide.
I did find out:
The F body arms use rubber bushings and they are the same as the B body bushings. BMR can and will sell you rubber bushings for the B body and you can use them as a 1:1 fit.
Conclusion: I purchased the BMR trailing arm kit (comes with sway bar bolts and lock nut and poly bushings), rubber bushings added to kit, and the hardware kit to mount the trailing arm to the frame/axle.
Will report back when I get everything and let y'all know how it goes.