Not London buses but I got a bus driving job specifically to make me more attractive to the rail industry and I've had much better fortune with rail applications since I did.
I do enjoy it on the whole, especially when I'm driving one of my regular, more out of the way routes. You get to recognise the regular passengers, and they you, and you can build a rapport with them. Sometimes your the only person they'll chat to all day and it makes you feel pretty good when they say you've made their day by remembering them. Other days you'll forget all that when someone hurls abuse at you for something random and not to do with you, such as some other company's bus breaking down. Other road users... Mostly just ignorant. Some go out of their way to make our life difficult, which is odd. Some very angry people behind the wheel for some reason!