I am interested if anyone has experience using a hook-on seat such as the Graco Tot-loc or the Chicco hook-on chair. My husband doesn't think they look very stable but they appear to be better-made than the traveling bootser seats by First Years and Safety First. I had a first years fold-up seat with my oldest daughter and it fell apart after about a year's worth of use. Any info on these seats would be appreciated. Thank you!