I have a screen house that I sometimes use as a kitchen. The problem I have found with mine is that the side walls are on an angle, so if it rains, the water comes straight in and you have to move everything into the centre of the screenhosue to keep it dry. Also, it doesn't stand up to strong winds terribly well. If the weather is fine however, then it's great. It's a bit of a pain to put up, but still only takes about 10 minutes. Since purchasing mine I have seem some great ones with the fold out style frame. You can also purchase optional screen walls to attach in bad weather. These would be far easier to put up and down, and would also be great in all sorts of weather, however I believe they are around the $250 mark, whereas mine was only $79.
It's all fun and games until someone gets hurt - then it's bloody hilarious!