I'm looking at picking up a jap copy of Forgotten Worlds. Question is do I need to get one with a 3 button controller to get the most out of it?- i've got a Duo RX with the 6 button controller, but I have a feeling that won't cut it.
Whether you're resting two fingers on a III & II button or Run & I, I don't think that it makes much of a difference.
True, a 3-button controller isn't essential, but since the Run button has a distinctly different feel (the fact that it is "rubberized", smaller, and a stiffer tension in the spring), I find the 3-button controller to feel much kooler.
As I said, it isn't essential, but I guarantee that you'd take the time to switch controllers -- even if you had to climb into the attic and pull it out of storage (as I did recently)! I have a third-party 3 button as well... it feels really sweet as well.