I don't know if I will be much of a help because I haven't put a baby in ours yet, but we have the Kolcraft Countours (single). We've messed around with it, and it has a really smooth ride, feels very stable, and our carseat (Chicco) works perfectly with the carseat adaptor. And the basket on the bottom is larger than most strollers and I am confident I can put quite a bit of stuff in it. My only initial drawback is that it is kind of hard to fold up and unfold and somewhat bulky (it BARELY fits in my hatchback). I'm sure any two-seater stroller is a little bulkier and tricker anyways.
I have the single, and we didn't use it a whole lot, and after a year of use it is starting to show its age. If I had to do it over, I'd have gone with a more expensive (but better quality) brand. I also HATE the straps. Cheap and poorly made. They are finger-pinchers waiting to happen!
Re: Opinions on Kolcraft Contours Options Tandem?