I am trying to get back to learning AVID ( I currently use Adobe Premiere) but the version I have is pretty old (MC 5.5). I was wondering if it was worth re-learning MC5.5 or if I should just bite the bullet and upgrade to the newest version? How different is the newer version?
You really ought to learn the newest version. The way you import media is different. Support for current cameras is present. Many timeline tools and functions are different. 5.5 might give a base on how to navigate the app, but plenty has changed.
Honestly, you can still learn a good chunk of MC from that version.
The only thing added to my personal workflow is Frame Flex.
If you need to brush up, start with what you have then move up.
I am sure there are a ton of other options if you decide to go deep but the core editing options are still at 5.5.