Ya, it's pretty noticeably busy downtown for these events. GO is getting some good use too, but they really need to offer a slightly later train for concert nights. We looked it up and noticed there was the last train the other night at 11:23PM which isn't late enough in my opinion considering many concerts let out between 10:50-11:00PM and it's about a 10-15 minute walk from TD Coliseum to West Harbour. Considering you don't usually get to walk straight from your seat to the street in 1 minute, it's a bit tight. They should really try to have the 11:23, and a 11:43 or 11:53 train.
Overall though, it seems like things are going well. If this keeps up, we're likely going to see a ton of vacant units filled immediately as the summer is going to be packed downtown.