Hopefully a new stadium will be designed with concerts in mind. I was at the U2 concert in Moncton and was very unimpressed with the venue. Aside from it being a big field with a sight slope to the stage nothing else worked. Transportation was a nightmare with very limited access in and out, the communications of where to go etc. were non-existent, the food, beer & washroom locations were unworkable. At midnight in pitch dark conditions there is no lighting etc. to exit by. Oh, and of course when you do find your bus/shuttle etc. expect to wait 1-2 hours to get moving.
I would rate the site at 25,000 spectators max.
Very bad access to Magnetic Hill:
http://maps.google.ca/maps?q=Moncton,+Ne....15369&sspn=51.277416,95.537109&t=h&z=15