K.M.
I have the Bob Revolution with 16" tires, and wheel it once or twice a day both up and down one flight of stairs. My two year old loves this, she says, "bump! bump!" on each step... We are sadly selling it tonight (less than two hours on Craigslist) and just purchased the Britax B-Ready because #2 is due in November, and my main concern is whether I'll be able to get it up and down very easily! Good luck- I highly recommend the Bob all around. My daughter loved it.