I have not started to use Java 7 but I have started to read on the differences. This is a great blog post to learn a few new tricks to optimize the JVM:
http://marxsoftware.blogspot.com/2011/10/javaone-2011-definitive-set-of-hotspot.html
It is also funny that the small, almost irrelevant, option is the one that will relieve a serious pain for me:
-XX:+PrintGCDataStamps If this works as I expect we will be able to read GC logs and easily figure out when events have happened
Cinq 