I've never gotten into the WASD thing. I much prefer the mouse. It's easier in my opinion.
I'm curious though...
How does using a finger to press down on the W key make you feel immersed while using a finger to press down on the mouse button not?
It's more natural movement when you get used to it. W moves you forward, and moving the mouse moves your head left to right. A lot smother than a joystick. But I agree, there for a 3rd person dungeon RNG style game, mouse pointer is better. WASD wouldn't suit this game.