He could have been gimmicky and annoying, but they somehow managed to give him a personality that wasn't either of those things. He does seem to enjoy bossing when he's allowed. Like when he runs for president in The Well-Mannered War.

OT: I've been thinking about whether the Doctor might have visited Susan after all. I keep imagining a story where he visits her once every regeneration. He'd always go alone, except for Four, who brings Romana along.