Just going to throw this in here to why people, specifically urbanists would move here. I mean you're getting the best possible service of transit you'll find anywhere in the city with the Graham/Main bus stop. I'm assuming most people that would live here would own a car but an upper-middle class person who hates driving and doesn't want to deal with the additional costs of owning and maintaining a house or automobile can live a car-free lifestyle quite easily. Even the bike lanes are good (as long as you make it to Garry St) Not to mention walking distance from Canada Life Centre, Exchange District, and The Forks. The amount of amenities that are nearby is borderline insane. The thing is this area is only going to receive new development and will be within walking distance to future BRT lines Union Station and Portage & Main. This building won't be fully occupied for a while, but I am almost certain it will fill up as it ages.
God forbid, some people here want to live a more sustainable lifestyle like reducing individual emissions and living in a place like 300 Main almost guarantees that. It is like the ideal urbanist lifestyle. We're about to figure out how many people with high credit scores in this city are urbanists
Also, 300 Main has some quite notable commercial tenants. Goodlife Fitness and Earl's aren't staying there for free that's for sure.