Ground Controls are the best - Never riden on a 2gnt with GC's but have compared 2 Si's: 1 with skunk2s and 1 with ground control and the ground controls were much better feeling. Ground controls can also go lower than skunk2's. GC's use eibach springs. I have ONLY heard good things from 2gnt owners that have GC's.
Skunk2's are over-rated and didn't ride to well, this is my opinion.
I have personally going with maxspeed because I believe they are closely modeled after the ground controls but at 1/3 of the price. $134.98 shipped. I just ordered today.
------------------------------------------------ 98 ESi 95 GS