I've deeeefinitely noticed gains on casematching polini. and others. but it's gonna be topend in the high rpm. if you're stuck at 8k on a polini, that's a bigger problem than whether it's casematched.
basically, you're not feeling the gains because that wasn't your weakest link. It's obvious if you're getting better action sans airfilter that you've got room to improve your tuning, and timing too i'd suspect, and i'd be down to second improving your exhaust - that makes a huge gain especially when it's more inline with the powerband your cylinder's trying to push.
so yeah - you're not feeling it cuz you're not done. much optimization left, but be glad that that step's already taken care of!