I use GF3.1 as they are the only one that implement JEE6 in full. There's an issue with deploy/undeploy app (memory leak due to pushing ClassLoader to the edge) which is kind of annoying to me personally because we do frequent build/deploy. I wish we can use Jetty (I used Jetty, Servlet, GWT in my previous company) since it is way leaner and faster to reboot; especially via Maven.

Although I've never measured the deployment performance, I'm quite sure the smaller your EAR/WAR size the faster it deploys because the ClassLoader is required to scan + load those libraries (again, it depends on the behavior of your library: up-front or lazy loading).