I switched out my tranny fluid for Redline MT-90 last Fall (~52K). I have also noticed the louder whine that was referred to earlier. No big deal and not annoying by any means and if you listen to every little ping, clank, whistle, whine, or creak your car makes (like me), you can hear it. Made the shifting a lot easier, especially in cold weather but I still think it's too notchy for my taste (and yes, I have the Kartboy bushings) but I'm not rushing to replace the tranny oil again anytime soon.