Stick or Twist: The programming language dilemma

Tapestry isn't standard Java, it does its own class postprocessing. As a result a lot of the advantages of Java go away (e.g. standard Java tools like debuggers and profilers don't work reliably), and code becomes virtually impossible to reason about.

Furthermore the design of components is backwards, making it impossible to properly encapsulate reusable components. I forget exactly how it worked, but I remember that you had to pass parameters down from parents to children, and because of the way variables were passed data ended up alternating through html-like files and java code, making it very hard to see where a given variable had come from.

After a month or so of that we switched to Wicket, which remains the best web framework, and quite possibly the best object-oriented library, I've ever used.