I came into Who a true blue scifi geek with no previous history with the show and in one episode RTD had me so wrapped up in the character and story of the companion that the Doctor with his TARDIS and sonic screwdriver was just a happy addition later on. I was hooked without even seeing him. Rusty tends to do that with all his characters. Even the guest stars and smaller roles. He doesn't make everything about the all encompassing persona of who and what the Doctor is. He fleshes out those around him. Gives them layers, depth, strengths and flaws. RTD's writing isn't just about plot, action and visual effects. The people make his stories and to me that takes more talent then a thousand impossible actions sequences. In my opinion, Rusty's care with characterization is a huge reason for new Who's success with scifi and non scifi fans alike.