I have the Strider (4 wheel) and loooove it. However, it is on the heavy side and pretty wide. I wouldn't want to have to be taking it on and off trams too much. But then again, I wouldn't want to with any pram. might I suggest using a carrier (like an Ergo) or sling for when you're taking public transport. That would be my preferred option, it's what I did when travelling in Europe. But it might not suit everyone.
Sasa