I went here recently to go see and Michael Buble and the concert itself was fantastic. We had return bus tickets from our hotel to get there and this was no hassle - unlike before when I had been and had to use the Tube afterwards which was a nightmare!
The venue itself is fantastic, and lovely even if you are not going for a concert with a great range of bars and restaurants.
Obviously it is overpriced inside from vendors if you are seeing a concert. I had been given a £5 voucher before I went for food and drink and spent all of this on two bottles of water (!!!!) but this was the only thing I could fault.
Staff there were very helpful and I would most definitely visit the O2 again!More