$50M for 6km of track construction from downtown to Bowness to Sunalta seems very light when you look at the actual conditions around Edworthy Park. I think continuous double track through that area will be cost prohibitive. We will hopefully see more detail when the CIB finishes their study.
To bring this back to the question of revitalizing downtown, regardless of whether it is a $0.7 billion or $1.3 billion investment, passenger rail to Banff would place downtown Calgary much more firmly on the typical tourist route. I think it would do a lot to bring another source of foot traffic at off peak times, and would complement residential conversions, post-secondary expansion, and greenfield development of the parking lots along the rail corridor. A direct train to Canmore and Banff would be a great selling point for apartments and for universities.