recentlly i am reading the book Mastering JSF. jsf is really a new amazing framework i think. it can coding just like swing style. and no more interfaces or super classes to care about. but i have a doubt here. i hope someone could tell me. as the jsf need to generate or restore a components tree and iterate the whole tree, and encode or decode the value binding to component, also using the reflection api to invoke bean method...blablabla. those are all heavy tasks in server. so how about the performance? jsf brings us creating the faces through drag and drop, component, event...so what is its lost?