It's a suburban mall and casino, which are both heavy trip generators, in a area with poor transit connectivity.
A GO Train line (which is a priority to be electrified too), 2 streetcar lines, and one of the busiest bus routes in the city is poor service?
At best, the proposal does little to integrate the development with the rest of the city
I don't get this. One of the biggest objections to the Oxford proposal is that it's not suitable for the area, despite it's attempt to integrate with the rest of the city. Now we have a proposal that tries to 'cordon' itself off from the rest of the city, and it's slammed for not integrating. Which is it???
Assuming a casino is going to get built, either the city goes with an urban proposal and accepts the fact that it may not jive perfectly with some of its neighbours, or it goes with a more suburban proposal that cordons itself off from surrounding uses that it may not jive with. You can't have it both ways. You're not going to see an urban proposal that is on its own little island (figuratively speaking), because an urban proposal involves density, which in Toronto involves either condos or office towers. Neither of which would work well at the Ex at this point. Maybe if the Ex were significantly re-imagined it would, but at this point, no.
Personally, I like the idea of the Ex location better, although I may not like some of the specifics of this proposal in particular. I like the idea of creating a 24-hour entertainment destination for a wide variety of events and attractions, all in a place that is relatively secluded from incompatible uses. It's easily accessible by both transit and by car, and it's easy to create a 'bubble' around it to keep everything inside and stop it from spilling over into surrounding areas. Geography and built form pretty much guarantees that.
If this does get built, I can definitely see myself spending the occasional Saturday night there. Go out for dinner with some friends, go see a show (Cirque du Soleil was mentioned as a potential permanent tenant), hit the blackjack tables afterwards for a bit, and then maybe finish up with a couple pints. Sounds like a nice night out to me.