Well I found even outside of actual relationships, people in Vancouver are much friendlier. I moved to Vancouver from Montreal with a roommate who'd grown up in Montreal, and it took her well over a year to accept the fact that when people in Vancouver are nice to you, smile, etc. they're not being fake, they're actually being nice. She didn't understand, because it doesn't happen in Montreal.
In Vancouver, I find that people will be more open to starting (or participating in) conversations on the bus, being asked for directions, chatting at a cafe (including baristas, cashiers, etc.), and so on. In Montreal, even with those people who did speak English, the attitude I saw from people was generally 'get out of my face'.
People in Montreal, in my experience, are absorbed in themselves and have no interest in anyone around them. They won't (as a rule) try to strike up a conversation on the street, they won't offer to help you if you're having trouble e.g. carrying a package, they won't hold doors. There are exceptions, but they're much more rare than in Vancouver, where everyone generally seems pretty content with their lives and is happy to lend a smile or a helping hand or a compliment to someone they've never met before or will again.
The other reason I enjoy Vancouver quite a bit (aside from the weather) is the living accommodations. It's said that the cost of living in Vancouver is higher, but from my point of view it tends to be pretty close, in the sense that you have to pay more in Vancouver but you also get nicer places. In Montreal, there is no 'damage deposit' when you rent an apartment, so there's much less incentive to be careful when you live in a place. Likewise, if there is a problem after you've left the landlord has to pay for it out of pocket (or try to fight with the tenancy board, which is a futile endeavour for small sums). The places tend to get run down and stay that way for longer. Even most 'renovated' places I saw were below what I'd consider liveable. The cost of renting a place is convenient though, considering that the wages in Montreal are (often considerably) lower than in Vancouver or Toronto.