I am evaluating web frameworks for a long time now. I wrote my own (not open) frameworks in Perl and in PHP. Well, PHP has a builtin deadend and the whole infrastructure is still quite poor, but I did not want to go back to Perl, so I checked Python and the Python Web Frameworks like Django, Turbogears, Pylon and web2py. There are many things to think about, if you want to choose a codestack that is not your own and you will often scratch your head because there is still no "right way" to program things. However, web2py is my current favourite, because the author, despite beeing a "real programmer", keeps things easy! Just look at the comparison on web2py site - I was wondering why python frameworks like django or turbogears had to introduce such redundance and complicated syntax in their code - web2py shows, that it IS in fact possible to keep your syntax clean and easy!
@Armin: could you please specify you criticism? Where exactly do you see web2py "bypassing Python semantics"? I can not understand, what you mean. I must admit that I am not that deep into python right now, but I see no problem with the web2py code - in fact, I think it is brilliant and one of the best frameworks available today.