People are addicted to it, I myself am one of them. For instance, take a popular map, The Hunted. But, waiting along the path are tons of sniper points, and the elite snipers to fill them. Being the hunted is one of the most nerve wrecking things there is. Just knowing that your next move could be fatal.
Control is pretty easy too.
It is your basic FPS configurations, but the fact that you can bind keys to make you say different things is one of the best features ever. And you can use them to let your team's medic how much health you have. I would say that you would at least need a 56k connection, because of all of the patches being released constantly, there has been a growing lag issue. TFC uses the Half-Life graphics engine. I'm not saying that it's bad, I'm just saying that it could be better.