We are beginning to build out a webapp which will probably see a lot of traffic. We dont have a lot of money, so we want to reduce hardware cost. More or less, I think that means we will try to be as stateless as possible (as the Wicket way suggests - have bookmarkable URLs, etc. etc.)
The other problem is that we are gonna be hiring contractors (think oDesk or elance) for chunks of work - so there is the question of finding talent.
I have looked at Tapestry and seen a lot of API instability ( see: Why did you stop using Tapestry? ) which makes me reluctant to use it.
Seam and Wicket are highly stateful - not something I care for.
Grails looks to be very interesting. I know that there is a performance hit as compared to pure Java, but it might be worthwhile.
Stripes looks good, but I cant find examples of websites that have been built using Stripes
Which Java framework do you recommend for performance and simplicity ?