ZZP shift kit
I have the ZZP kit as well. I'm not that impressed with it. All I feel it did was make the down shifts faster, I can't say that I've felt any change in up shifts at all. Good thing it was only 30 bucks! Ill probably remove it next trans filter change, that is if my trans lasts that long!!!
I just got my ZZP one today. All you are really paying for is the SPX FILTRAN filter that comes with it. Those nylon bushings cant cost them more than $0.50 to produce. There is only so much a ZZP shift kit can do because you are still using the stock springs for accumulator. The accumulator is a shock absorber for the shift valve fluid in a specific gear. By using a spacer, you are shortening the travel of the shock absorber which means the shift valve moves sooner.
If you are looking for noticeable improvements in overall shift quality and speed, get a Trans Go kit. If you just want something to make a slight difference, get the ZZP. I only bought the ZZP because I just bought my car used and I'm going to change the trans fluid and filter anyway. The whole kit from ZZP was cheaper than I could buy the filter for from my work. I'm just gonna put the smallest bushings in to help prevent premature clutch/band wear. When you start getting more serious with the shift upgrades, you need to upgrade your hard parts as well.
What a lot of people dont realize is that the upshifts will usually feel smoother than the downshifts. Thats because our cars use TAC motor instead of a standard throttle cable. The ECM software slightly closes the throttle plate during a shift and then re-opens when the shift is complete. This is the same principle you use when driving a stick shift car. It helps to rev-match to the next gear which allows for a smoother shift and less shock load on a trans. When the computer is intentionally making the engine "let-off" during the shift, a shift kit can only do so much on an upshift because you are defeating what the ECM is trying to accomplish. To my knowledge downshifts still function as they used to in all cars, which would explain why your downshifts are more noticeable.
