Originally posted by: andy_k_250
but when I noticed no difference in my dl/ul speeds, I closed them again.

You won't notice any instananeous speed boost. Opening up your firewall (ie port fowarding) allows people to connect to you. When you are behind a firewall, you can only make connections to other peers and nobody to can connect to you without you connecting to them first. With more people connecting to you, that means you have more peers to grab data from. Which in the end, means you'll get stuff faster.