Self Transfer in Toronto with WestJet and Air Canada - worth the risk?

I'm traveling to Mexico City from Dublin in May and have left it last minute to book a flight so the prices have gone up. I was originally looking at booking with British Airways with a flight to London and then direct to Mexico which would not be a self transfer but the price is now almost €1000. There are flights provided by WestJet and Air Canada that are only €400 but it is a self transfer in Toronoto airport. The layover time is 6 hours which seems like a reasonable amount of time to clear immigration, collect bags and check back in but I'm unsure if it's worth the risk? It would be great to save that amount of money and put it towards the trip but I've never flown WestJet and don't know how reliable they are for time keeping or last minute flight changes that could effect our onward flight. Any advice would be greatly appreciated! :)