well in general its a very difficult task to critisise, i think you need to
do this in comparison to something else, even if that is classic ASP.

Some of the negatives are the move to a fully typed object orientated
programing language, the tie in to microsoft technology (I know there may be
a common runtime for other platforms but i wouldnt count on it), you do need
a pretty decent spec machin to run the framework etc etc.