ALL TIMINGS DONE ON SNES9X 1.53 EMULATOR, TL;DR AT THE END


J saves 1162 frames (19.4 seconds) in loading times over U during the course of the entire run. There is some variance, but the rule of thumb seems as follow:

1)Entering a stage is the same speed on both versions (some exceptions like Arich and Kaos...).
2)Exiting a stage is ~17 frames faster on J.
3)Entering Funky is ~27 frames faster on J.
4)Stage transitions in water stages are the same speed on both versions.



Now for other version differences

JAPANESE IS FASTER IN:
1)Boat movement - most notably after W2, after W3 and after W4 - is faster on J. While hard to time, it seems to add up to roughly 100 frames over the entire run. Why? Because on U, the turning is awful slow, and the acceleration after W4 is dreadful.
2)The ending of 3-5 is faster by about 8 frames on J (comparing both optimal endings).
3)Entering World 4 loses about 8 frames on U, due to Dixie stopping at the Bear cabin.
4)In 4-4, you save about 90 frames due to not having to wait for bees (Since these bees can be skipped with relative ease, this time save will be considered conditional).
5)In 5-2, the ending barrel shoots you further, saving about 22 frames.
6)In 7-2, assuming you get perfect RNG on the very last ghost barrel, you save 31 frames.
7)The Krool Speech is faster by about 90 frames.

Total: 350 frames (+1162 frames of loads) = Roughly 1512 frames saved



NORTH AMERICA IS FASTER IN:
1)Swimming to Wrinkly is 3 frames faster on U, despite the music playing longer.
2)Talking to Funky is faster on U, adding up to about 15 frames over the entire run
3)A 2-cycle Kaos saves about 1590 frames (26.5 seconds) over an optimal J fight (same-side blade on every cycle).
4)In 4-1, U doesn't grab the DK Barrel, saving 33 frames.
5)In 4-2, the ending section is about 30 frames faster on U, due to being able to get past the bees.
6)The Bear in world 6 is faster by 131 frames, for whatever-ass reasons.
7)In 6-4, the Booty Bird placement near the beginning allow you to save about 5 frames.

Total: Roughly 1805 frames saved



TL;DR -> The North American version is faster by ROUGHLY 293 frames (4.9 seconds), accounting for what I think is everything.

Note that this can be brought up to 6.4 seconds if you successfully skip the bees in 4-4 on U.
And then to 6.7 seconds if J does not get perfect RNG on the last barrel in 7-2.


PS: A 1-cycle Kaos would obviously save a billion.

DISCLAIMER: THOSE TIMES MIGHT BE DIFFERENT ON CONSOLE, BUT THE RATIOS SHOULD BE ROUGHLY THE SAME! AND I DO NOT CLAIM THOSE NUMBERS ARE 100% ACCURATE, AS THEY WERE NOT PEER-REVIEWED! DO YOUR OWN TESTING YOU LAZY FUCKS. Love you all.

-Djeez