A great service
If you had asked me a year ago whether visibility of what buses were arriving where and when would be helpful, I probably would have been lukewarm.
However, having recently consumed the service via mobile apps it is genuinely useful because you can decide which bus to take from which stop, or whether to walk or get a tube. It sounds trivial but for a city the size of London it's a big deal: there are so many bus users and each gets a little bit of benefit.
Good work TfL.