I put off buying a stroller until my daughter was 1.5 years old. But she is getting heavy and I wanted her to be able to sleep while we were out. She fell asleep on her first ride home--bliss.
I can lug this stroller and my daughter up the 4 flights of stairs to our apartment -- is it fun? No, but it is doable.
If you are a big proponent of baby wearing this could be the stroller for you. Its a bit pricey at about $200 but it's lightweight, allows your baby to sleep comfortably, and is very compact. Its the perfect combo if you want to carry your child most of the time-- or get them to walk.
The only Con I have found is that it is tippy--which makes sense because its so light weight. It is fine as long as a child is in there-- but take your baby out before you take your bag off the back if it is at all heavy. But keep in mind that I use it to buy my groceries and can load a frightening amount of very heavy items on the handles without it tipping over as long as she is in it-- so while its tippy its totally useable.
I really, really wish someone would invent an umbrella stroller that could face back and forward that was just as light weight (and while we are at it that you could jog with) but until that day comes I think this is the best lightweight stroller on the market. It looks just as comfortable for the baby as the city mini at almost half the weight, and is even more compact.
Reviews will tell you that it stands by itself and has a cup holder-- all true but although I was excited by this neither of those features have been useful to me.