Upgrading to Java 9

Ever since Java 9 was released last fall, I have been wanting to upgrade our software at work to the new platform. I am not interested in the new module stuff, mostly I just want the convenience methods like List.of(), and the platform improvements. I think G1 by default looks good, the new representation for strings to save memory looks like a huge win, and all the performance numbers that I have seen show it to be a big win. Unfortunately this is not as straight forward as one should hope.