Love the vista. I only have one child, but it is lovely. They just released a Rumbleseat+ that allows for up to 40lbs (instead of 35lbs) on the bottom which is nice, and would've helped in my decision between the Vista and another high end comparable brand that has higher weight limits. Still went with the Vista. I do think, based on friends, just do a single stroller to start, and see where life takes you. Love the stroller though, and have heard great things about their customer service.
To note: It is massive. I have a midsize SUV, and it takes up half the trunk. Second, every little piece is an additional cost. This seems somewhat of the norm now, so I didn't deduct for that.