Well, it depends. In most cases, a Gemeni converter works fine. However, the timing on Ultramix is even stingier than 5th mix. That is to say, that regardless of how you THINK you're on beat, you will miss steps that aren't "Marvelouses." If you think your steps are alread "perfect," then go Max 2.
If you think you have room to improve, go Ultramix. Also, you may want to set it to +1 depending on the lag time between adapters (CF metal pad through control box through Gemeni makes a milisecond o lag). Also, if you decide that no adapter is good enough for you (all of them will register you as a controller online with no headset), then you can look up Mastermind3k's forum on how to disembowel your bundle-in pad to make a control box that is perfect in every way.
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