Powder Hound has been running redline for more than 200K miles?
I know I read here that redline causes our brass synchronizers to fail, but obviously that's not a sure thing.
I ran a mix of two redline transmission fluids for about 10-15K miles and drained it in favor of OEM fluid. It was too gummy when cold but really nice when warmed up. The OEM stuff (G50, G60, G70) all seems to be less viscous in cold weather. Redline is made from a different chemical that I believe is good at grabbing the dirt in the transmission. I recommend running it for a short time (10-20K miles) just because it seems to flush out your transmission.
All these recommendations are merely my seat-of-the-pants observations based on transmission function and the color/smell of used fluids.