Moving to AC would allow the OP the opportunity to play Aerolotto for an upgrade on longer domestic flights (score one point for AC). However, it sounds like the majority of OP's travel will wind up being on single-class prop planes. Personal opinion is that Jagboi's right - Westjet's 737 beats AC's Dash 8 every time, so score one point Westjet. Tie game.
OP already gets a bunch of lounge passes each year, while AC status gets the MLL. So that's a wash. Game still tied.
OP identifies about $1,500 in return value from current Westjet travel each year. So the question is, will AC save $1,500 a year when buying all travel at Flex or higher fare classes required to score that coveted 50k status? If so/not, then there's the answer.