yes I do agree with you. a 1 way adjustable will never be as good as a 2 way adjustable. and a "home made" system will never out due a well engineered threaded coilover system. but I still drive my car on the street. And 1g for a street car isn't bad. I will soon go to the double adjustable adj. konis. as soon as I blow my single adj. konis. but to be able to catch up to a porsche gt3 in the corner isn't bad.
BUT the good thing about ground control is that their springs can be traded very easily. I have experimented with different rates and this set up suits my driving skill. plus I can drive to ucsb the next morning.
But I wouldn't underestimate koni. I have seen really serious cars and their owners boasting about how good koni is. especially the honda challenge guys here in california. at tracks like thunderhill, willow srings, infineon etc.