Some people say yes...others say no...apparently if you notch the reed cases you can
get the same results...Personally I purchased the spacers..and added some carbon tech reeds...did it hurt the performance...no...did I see gains...kinda...nothin dramatic...but took off some of the "throttle Pinning" burble...
Personally I think every little thing helps...Goodluck
i think there is a gain from the bottom to mid , like said above not a huge but it does get rid of that little burb when you hit the hammer . one thing i would do if you do use them , go out and buy bolts that are longer by thw width of the spacer , stock bolts didnt seem to get a good bite after the added width ..