The big issue I have with Wicket is that it seems more suitable for the web we had 5 years ago than the web we have today. These days we have static html/css/js that accesses data through a json api. Wicket is really not a good platform for this.

If you like the Java ecosystem and really want some top notch tooling, I'd recommend the following:

  JAX-RS for the JSON API (eg Jersey )
  Atmosphere for data push and updates (pubsub, websocket)
  GWT for the frontend html/css/js (good integration with
    Jersey via RestyGWT)

Wicket isn't suitable for highly scalable or single page applications as is (the ones which benefit from a rich client side and a stateless API approach). It is highly productive for typical backoffice applications though. The only problem is the complexity of the framework - writing custom reusable components is really hard.