Anyone have experience with a Sit 'n' Stroll?

[electriclady]

DD (14mo) will be outgrowing her Safeseat in the coming months, and I'd like to get a convertible seat before a cross-country trip we're making in July. I was thinking of getting a Sit 'n' Stroll for the plane trip (and possibly taking a cheap umbrella stroller as well) and am wondering if anyone else can weigh in on the pros and cons? Ease of installation?

I'm also considering making it our primary car seat--we don't own a car (live in NYC) and use a car seat maybe once a month at most, for the occasional cab ride or driving to Grandma's house. How is it just as a car seat?