Some of these bikes are fine, but you won't be getting them on a bus, even thought they fold. I had the Magnum. Too heavy imho. I have a Vika +. No complaints, but there's no way I'd be comfortable lugging it onto a bus. I think you'd be well suited seeing some of these 20 inch models in person. They aren't as compact as their press releases and videos lead you to believe.
That said, if you decide that bus/trunk transport isn't important, your choices increase dramatically.