We have one, and for our lifestyle- walks around the neighborhood, summer festivals, etc. it has been great. It is too bulky for me to use as a day-to-day stroller, so we also have a Maclaren. It has been great for general outdoor usage, but I've never actually ran with it.
TTC#1 since Mar 2008. Serious MFI due to cancer.
3 cancelled IUI's, just about every test in the book.
IVF#1 - BFP! Twin girls arrived 2/5/10 at 35w2d.
My twins are 3 1/2 and I've had it since they were newborns. We have used it on a daily basis for walking and running around the neighborhood. It is good for that, but too big to fold up and take places so you need another for malls and stores and such. It is a good stroller for the money. I have had to put on new tires because the old ones wore out, but you can buy bike tires and tubes and walmart and it is super easy.
Re: InStep jogging stroller?