I currently have Pro version 4.3.3 with 15 drives plus parity for our home family media server. I want to add an additional drive and was told maybe a year or so ago I had to download and upgrade to some newer version of 4. I am concerned about being down so I first copied the thumb drive to another and tried to boot off of it, so I would not mess with the original. But that did not work. I thinking about just buying the update on stick so if I run into any issues, I can simple put the original stick back in and reboot. SO my question, is where do I find a list of what are the new features and is 5 or 6 the latest? Is it literally just a plug in the new stick and boot, then add the 15 drive and parity back to the devices. Or is this a major thing? Advise please.