Keep HKS bov or what? or greddy?

[Evolution8David]

I had my HKS bov on my car for over 8 months now. Its been venting out to atmospher ever since. Learned how to drive the car with the stall problems. Since im aiming for 350 WHP right now, i hear i lose power with the HKS BOV. So im thinking, should i sell the HKS away and go MR or buy like a Greddy type S or RS? Does the greddy have problems as well? and S and RS what difference?
thanks

-David