One-hand fold lever
And then I fell in love with the Mountain Buggy Duet 2015. The truth is that the 2014 version was perfect enough (and it was on sale), but I love the new one-hand fold and seat liners the 2015 version has so I splurged to get it. Why was the Duet the best choice for me?
The narrow width, obviously. The stroller is just 25" wide - the same as my Uppababy Vista! Realize that the seats are narrow as well. This wasn't an issue for me because my children are just 19 months apart and my toddler is small for her age, but if your older one is bigger than that, then he/she may not be very comfortable in the Duet seat.
Huge basket
The basket underneath is plenty big enough for everything I need and the adjustable handlebar is super convenient. The seat reclines pretty much flat and I use it for my infant with an infant insert. The harness is really simple for parents, but too difficult for a young child, making it really safe. I was a bit apprehensive that the canopies would provide enough coverage, but they really do!
The Duet comes with air tires, the only drawback for me. I don't like air tires at all, but you might. Mountain Buggy does offer a set of 10" aerotech tires available separately.
Bottle Holder
Along with the new duet, Mountain Buggy introduced their Duet Carryot Plus - a carrycot that turns into a parent-facing seat so that you can see your infant. Mountain Buggy also upgraded their Joey sidebag that can be placed into the Duet frame instead of one of the seat giving you tons of storage space when you are out with only one child. If you will travel a lot with the stroller, I would recommend using a car seat adapter to make going in-and-out of the car so much easier with a baby.
I'm really happy with my Duet and my daughter is super proud to be sitting next to "her" new baby:)
If you have any questions at all about the stroller, comment below and I'll do my best to answer right away:)