The impact of the Queensway on the ground is much worse in the inner suburbs than downtown... I find the inner city overpasses quite short and not much of a barrier. We even have separated bike lanes going under the Queensway. There could always be improvements but overall it's not bad.
However it would be an interesting exercise to see how the Queensway is being used as a cross-town route vs a feeder into downtown. You can see the data for the Gardiner here - only a small percentage is being used for crosstown trips.
http://www.gardinereast.ca/sites/default...ic%20Forum%20%231%20-%20Presentation.pdf
The argument could be that the urban redevelopment benefits would outweigh the small amount of traffic using the highway to get across town (if this is the case in Ottawa). One issue I see with this is that Toronto has lots of potential routes to get around downtown while the canal, rivers and railways limit Ottawa's potential alternative routes. Toronto is on a grid with few geographical constraints while Ottawa already has major issues with limited alternative routes (e.g. for trucks).