Just thought of something else. I've been running the diffs in the high position with the X-Patterns, to keep the axles straighter. It's not something I've thoroughly tested in isolation, but I seem to think it makes the car more predictable.
Of all the stuff I mentioned, though, I'd say the droop is probably the single most important. Droop will be different (on the gauge) compared to TC tires, becaue the X-Patterns are taller, and if there's too much (particularly in front), the car will just drive like poo on carpet. It'll roll alot and the front end will dig in and be really unpredictable.
-Mike