I've never heard good things about the larger displacements, unless someone threw on a 7D carb. When I have a bad carb on a Tower Hobbies engine, I opt for a OS replacement.
Generally I replaced the FX carbs with the older 4D carb from my SF series, interesting how the trend goes back to needle on the carb style in the AX line nowadays.
Super Tigre carbs are good. They have been revised more than a few times over the years. I have no trouble with the old Italian round head Tigres with the older carbs either.
I have about six of these now from .23, .45, .61, .75, and .90. They all run excellent, at all RPMs, transition good, and do not dead stick on me. I also run about 4 OS engines now as well on other planes, and these run out of the box, and require really no tuning in comparison, but you pay a premium for that.
At the flying field I tune other people's Super Tigres. I find other issues 50% of the time that would also effect an OS in the same way, except higher nitro content, Super Tigre likes FAI, 5%. OS runs on 10-15% usually, although I keep 5% and FAI for them as well, and they feel weaker on the stuff.