Since this is a side-based decision, I side with oromis because runescape is slow and boring. I got bored halfway through the tutorial when i first played it. Some people have different attention span levels while other want immediate gratification.
TF2 has immediate gratification, runescape makes you wait until you get leveled up/explore the entire 12-bit world. I like games where I use my arrow keys/WASD. and click on stuff when i walk to it i start doing whatever im supposed to be doing. Runescape is a game for the extremely patient and the extremely bored willing to try anything that isnt very difficult.
tl;dr TF2=instant action
Runescape=action VEEEERY later on in the game.