As near as I can tell the only difference between a TKO-RR and a regular TKO is in fact the over drive ratio. RR being a .8 and the regular being a .6. Maybe the TKO-RR is built slightly different inside? Heavier "whatever's" in there? I don't know, I just wanted the .8 for my 3:31 rear gear. I KNOW my cam profile and the way my engine feels if it drops below 2000 rpm, it aint pretty. The .6 OD would have me going well above most of the posted speed limits around here to stay above 2000 rpm.
My primary reason for switching was because I felt like I needed to do a major overhaul on my top loader. The TP works great, in fact I recently put in new synchro's and a second gear synchro cluster. But, it's got some hard miles on it over all, so... Time for a change I guess.
The car feels completely different with the new ratio's, I'm slowly getting used to it. The accelleration is certainly more "brisk" in first gear, all though, short lived, I need to shift way sooner than before! The new puck on both sides RAM clutch is the most agressive I've ever run. Is that a Kevlar thingy or a ceramic thingy or what? At first it was go or no go, in or out, launch and burn rubber or stay home.
I've got a hundred miles or so on it now, mostly stop and go to break it in and it is MUCH more user friendly now. I can control the engagement quite nicely with no chatter or complaining.
I would NEVER consider being in a parade before with the old top loader and the high first gear. The car did NOT like to "creep", I had to use the clutch a LOT in heavy traffic, man that did get old. The new lower ratios of the TKO are much more friendly in a heavy traffic environment, I'd consider a parade now.
I do miss the close ratio of the top three gears on the top loader when I'm "at speed" though. Downshifting in particular was really sweet with the close ratio, very little jerk or harshness, real easy to heel and toe and hit that rpm "just right". The wider spread on the TKO is a new ball game, you HAVE to catch that rpm "just right" on a downshift or you WILL have a harsh engagement. I could see locking up the rear and spinning the car out if you screw up a high rpm down shift with the TKO. That was pretty hard to screw up with the close ratio top loader.
I miss crusing along in fourth, about 65 mph on the freeway and then dropping it into SECOND gear and just blasting away! Yeah, you can make a strong case for the close ratio, it has it's place. Really sweet on a road course.