Spring is a huge umbrella project that contains many parts, some good, some not so good. Guice or picocontainer work well, but you can achieve the same effect by using spring's Java configuration and avoiding silly things (AOP, shudder), and that way you can migrate existing spring XML piece by piece.
If you're writing an actual webapp (i.e. something that outputs html) then I highly recommend Wicket; it's the most beautiful framework I've ever used, in any language. If it's just REST APIs I can't really recommend anything - by the time I started writing those I'd switched to Scala (in which Spray is wonderful).
I'm with you that Spring has ALOT of parts. At my company they allowed us to use some parts of Spring and not others. Our stack was Spring MVC, with Apache Tiles, serving JSPs with some JQuery in there all wrapped up with Spring Security. It was much better than what we had before, JSF and ICEFaces and ADF. JSF frustrates me to no end.
Now we're moving towards a more modern stack. Using Jersey for REST is nice. It does make me enjoy Java again. You annotate resources in a Spring-like way, security was easy to implement. On the front-end we use a client side JavaScript Framework, JMVC (CanJS, EJS, etc). JMVC doesn't have as much traction as other frameworks, like Angular or Ember, but it is stable and covers what we need.
But when I go home, I try to stay away from Java. It's mostly Python (Flask, Tornado, Twisted) or lately some Node (Express) on the backend and Ember on the front. It's psychological. I program at work for work and at home to have fun. For me it just feels easier and more fun to stream code in Python.
For rest services in java I really recommend Dropwizard. Wraps a bunch of great libraries together with just enough glue to make your development easy. Really great support for metrics.
If you're writing an actual webapp (i.e. something that outputs html) then I highly recommend Wicket; it's the most beautiful framework I've ever used, in any language. If it's just REST APIs I can't really recommend anything - by the time I started writing those I'd switched to Scala (in which Spray is wonderful).