You have to set up port forwarding on your router for BitTorrent to work properly, which, at the end of the day means faster. This only applies if you have a router, though. You need to configure the router to send traffic on ports 6881-6999 to a certain IP address, the one your computer uses (that should be static) on the same ports.
Actually configuring a router to do that differs from router to router, so a little more information is required. What kind of router do you use, if you use one?
Also, I like Transmission better. It is a simple, functional, app. It doesn't try to manage my downloading life life some apps do.