Funny you should ask...I just went through this myself.
We rented the double City Mini last May from Orlando Stroller Rental. I fell in love with it. There was nothing about it I didnt like. So when we got home we made plans to sell our other 4 strollers and buy a single. We sold the strollers and saved the money.
Fast forward to last week. I went to the garage to grab our little Maclaren, and my lovely 12 year old had snapped the wheel off. I needed a stroller ASAP so I could walk my kids to school without having to carry the baby. I did some comparisons, decided on the City Mini, then when I went to order it, I couldnt find anywhere that would ship fairly quickly.
We went to Babies R Us and tried out the Kooper. I love it. I love the way it pushes, folding is a breeze, great sunshade. And I love the little mesh pockets on the inside of the seat. Oh and the cup holders on the back. The only thing I wish, was that it folded flat like the mini.