Not even going to bother with the finances....     
From artists impressions it does look very good & I think I would be a major coup if AFC manages to get a new stadium like it... I am a bit sceptical that the finished article will be the same though. Some fairly major points however:   
Transport... This has been done to death  - but the fact remains that unless you are driving up from the south, the stadium will be a major pain in the arse to get to & away from games.  For those that do drive from the south i don't fancy your chances finding a parking space close by....   
Crowd segregation pre/post match....As with any out of town stadium - its a bowl with no 'fan channelling' streets away from it.  this won't be a problem for 9 out of the 11 teams that visit, but when the OF come to town it could be a different story.. Having been to the riverside a few time when Newcastle and Sunderland were visiting & witnessed the problems that occur when you have large groups of fans let loose in the same vicinity, i could see AFC's police bill for these fixtures rising..  Short of keeping away fans in I don't see a way round this, but even the 15 min dispersal time doesn't really do the job, people that want trouble will just hang about outside..   
As an aside - a way for AFC to make an absolute killing money wise would be to build several bars around the stadium  - given the location I'd guess they'd be pretty popular & it would be a captive audience.