I've seen him twice
First time was about 5 years all about the formation of the universe , bloke in front of me fell asleep , but I found it really really fascinating , even if some of it is a little hard to understand
second time ( current tour) is around the Horizons TV show , equally above my tiny brain cells but still interesting , talks about black holes and various theories that would have seen you in a straight jacket years ago , but now might actually be feasible
the value of the ticket is down to beholder I guess , but if you've watched Horizons on TV you might not be gaining anything new