That Ultima 6 speed and the Rev Tech are both Asian made, I believe Korean. Rev Techs were recalled about a decade ago for serious life threatening defects. I put a Screamin' Eagle 6 speed in my "02 Fat Boy back around '05. It has a .89 overdrive. I loved having a 6 speed when new Harleys still had 5 speeds! I still have that bike and it's pumpin' out well over 100 h.p. and torque. I get great gas mileage, and it has been stone reliable for nearly 60,000 miles.
To clarify the post about 5 and 6 speeds still being 1:1, that's misleading. Yes the new Harley 6 speed is 1:! but low gear is way lower than a 5 speed and the primary drive is quite a bit higher so r.p.m.s are reduced at the same speed in 6th gear vs a 5 speed. That reduces engine wear and improves gas milage. You will be roughly the same revs at 80 as you would be at 70 with a 5 speed.
It's your bike, your money, and your ass if that Asian tranny locks up at 80 m.p.h. I wouldn't replace a good Harley 5 speed with anything besides an American made Screamin' Eagle, Baker or Jims tranny myself. Sometimes cheapin' out ain't so cheap!