you shouldnt need to upgrade.
I have both, and I do really like the Kfactory one, but its a pain to get going if you dont really know what you are doing....this was my case, but I got it under wraps now.
just do a simple inspection of your car, pull the motor, and see if the clutch is assembled right, maybe the clutch springs are not on the right way?
Occams razor....the simplest answer is most likely the correct one.
Plus it seems hard to get Kfactory stuff now, so I would suggest sticking with the stock set up, cheaper and gets the job done.