I have a
BBK cold air intake, mostly stock motor (headers, exhaust, underdrive pulleys). When I bought my car I also got a brand new trickflow set up to include upper and lower intake, 70mm TB and MAF and 30 lb injectors. As you mentioned, I am suspect whether this is really worth the effort based on possible gains. I have stock heads which I know is a big limiter as well.
Honestly, I was going to throw in a 65mm TB/spacer only from the standpoint my throttle shaft has a vacuum leak and my motor is mostly stock. More HP is great, but I'd settle right now for the car to run better. New baby on the way is going to limit my tinker time for a little while.