In my opinion, it makes for a much better street tranny, especially in heavier cars. It saves on clutch life and just generally makes take-off a much smoother task. The wilder the engine, the more it helps. I'm not even sure why Ford put the close ratio behind big blocks, which were never intended for road racing.
Wherever the gears are made, the ones I've gotten have been pretty nice and I've not had any problems with them. Some years back, I had issues with the replacement blocker rings. They just didn't seem to work as well as the originals, which were getting harder to find. I think they had different friction ridges machined into them that didn't work as well. The current ones seem to work and shift better.