Of course, you can find out changes by reading perldelta. As for 5.6, I also have heard of the bugs and such and believe 5.7.0 (which will be a development release) is comming RSN. Maybe it would be good to wait and see what bug fixes are in 5.7.0, or just wait until 5.8. Thus far, I have stuck with 5.005 for all production code.