If you ever try any of the modern stuff (django, rails, play, grails, any node.js framework) in depth, j2ee / Spring and java just feels old and ancient. Spring has gotten better over the years, but there's still just too much work and too much unnecessary complexity and cruft with Spring. It's really telling when even Spring's creator jumped ship to work with TypeSafe and jvm7 has huge improvements designed for other languages.

imo C# is an improved java, but C# open source ecosystem is just anemic compared to java.