Opinions on aftermarket rear discs??

I am getting ready to enter the final phase of my car build...the rear axle. At the same time I plan on replacing the master cylinder, installing a brake booster, and I would like to convert to rear disc.

I was looking at buying a TSM Mfg. rear disc conversion it, but I have heard a few bad things about them. Is anyone using them, and what is your experience with them?

Vehicle:
75 Dart Sport
BBP wheels
8.25 axle front disc/rear drum (aren't they all)

This is a street car, with only occasional track use. I have thought about just rebuilding the drum setup, and using the money saved to get a set of front discs cryogenically treated with some good ceramic pads, since the front brakes take the brunt of the abuse. (I already have new front calipers).