I dunno about travel distance... Did Sunshine last year, and will definitely be doing it again this year, but the drive seemed a lot longer. GoogleMaps put it around 25 minutes longer, but I think it adds up to more than that with the detour you have to take right through Calgary. Jasper is under 3 hours if I speed most of the way.
It's also WAY cheaper to head to Jasper. Easily half the price... Although last time we went we did stay at Banff Springs which was not cheap.