It works pretty good. When I enclosed my pole barn, I left a 10 foot tall, 16 wide opening. Used the TSC track and rollers to hang 8 wide, 10 foot tall doors made out of 1.25" angle iron and skinned it with 26 gauge R panel. The door sections ended up being MUCH heavier than planned.
That was about 6 years ago. Doors still glide back and forth. And that is without a much needed bottom track/roller setup. I say much needed not because the top rollers cannot handle it, but my 2x12 box header is bowing outward and downward because of the weight.
I didn't plan it far enough ahead, so there was no concrete down there to place a track.
So my tip would be the rollers are great, but incorporate a bottom roller system. Not only wont you have to worry about sag, the doors wont bang every time the wind blows. I have holes in my walls from opening the door and a gust of wind coming by and the door catches one of the raised ribs of the wall paneling.