From their website's event calendar:
https://www.rogersplace.com/events/
In 2019, Rogers place has 43 non-hockey nights either in the bag, or already booked. This number will probably go up, as there are only 10 nights booked from July - December, but there were only 4 non-hockey nights in March and only 2 in April, so the number won't go up that much.
The Saddledome has the advantage of the Roughnecks, so let's discount them to start. The 'Dome has 27 non-hockey or lacross nights filled in 2019 based on their calendar:
https://www.scotiabanksaddledome.com/event-calendar So, Rogers does have an advantage, even including the 7 Roughnecks dates in 2019.
Broadly, the two arenas are getting similar acts: Cher, Backstreet Boys, Fleetwood Mac, Lynard Skynard, Def Leppard, 21 Pilots and Iron Maiden are all playing both venues.
Rogers is getting Ariana Grande and - judge me all you want - she's the one name on that list I'd pay to see. Roger's also got Cirque du Soleil which filled up five nights in February.
So, overall, the difference between the two rinks comes down to pretty much Cirque du Soleil and Arianna Grande.