I went on my first run on Saturday with the kiddo in the BOB Ironman stroller... ok-- I get all the hype now. When you are just walking with the stroller you don't get a feel for how light the stroller is and how easily it can turn when going at more than a walking pace. It was great! Granted, I did not have any major turns, but I am a fan of the stroller. It was smooth to run with and to turn.
Also, the adapter kit has worked just fine with the Chicco Keyfit carseat. My little man fell asleep and was out the entire time. I love that he faces me during runs, so I can see that he is asleep and how little his head moves even over a bump!
It takes about 50 times longer to get ready for a run with a baby, but it was well worth it... and bonus... it gives me no excuse to not get a shower in for the day. : )
On a walk one day-- he is in the carseat and adapter for walks (and runs) now.