I hate 3 wheel buggies. I like to walk fast - keeps me in shape, too - all my buggy use is urban, and there isn't a 3-wheeler around that can match a sleek 4 wheeler for manouvreability, ease of folding down - for stairs, public transport and getting around scaffolding or narrow pavements and shop aisles, and light weight. I need something I can push w/one hand, b/c so often w/babies you need another hand briefly - to wipe spit up or spills, hand over snacks or cups, straighten baby's hood or blanket, sip a drink, etc. If you stopped everything you had to do that, you'd get nowhere.
Need something that's easy to clean, too.