Whats the best power upgrade???

I have an cam and jet kit already. I am pretty sure most are going to say a pipe. I was wondering if its worth it for me because i dont want an obnoxiosly loud pipe since i use it to get near my tree stands. Can you still get real power without the noise. More noise = less restriction. Less noise more restriction similar to stock???????? Dont want to spend a pile of dough on a moderate power gain.

Thanks.