I've never personally run Rotella (or any diesel oil) in my bike so I can't speak to that specifically, but I'll say from experience with motorcycle specific oils, when the shifting degrades it's across the board, doesn't matter hot or cold. All the sudden you realize the shifter doesn't "snick" up into the next gear the same, you get false neutrals sometimes, and it feels rough.
Then you change the oil and the transmission feels brand new again. It can get so bad that it feels like something is mechanically wrong, and that's why a lot of motorcycle guys change their oil more often than the manual suggests. Like, my manual calls for 7,500 mile changes, but there's zero chance I'll ever do that, because even if the oil is safe to run, I still want that like-new shift feel again, and my bike only takes 1.1 quarts anyway. I change my oil about every 1,600 miles for this reason.