Yes, it's true that most studios keep older versions of PT on backup systems, and for whatever reason certain engineers will prefer certain vintages. I suspect this is because the layout and overall user experience changes slightly from version to version. This is my first version, so I'm using this latest incarnation and loving it. After being in so many studios over the decades and watching engineers work their magic, it's great to finally have my own system. Running on Windows 10 without issues knock on wood
I used to use Audacity but then at College they used Pro Tools 10 and I loved it so much. It was a professional looking software and it has so many options. My dad bought me Pro Tools 12 and I am always using it now for recording, I use it for recording my solo EP and my bands upcoming EP. People will give it crap but it is honestly perfect, it has everything and it is a simple layout, the mixing part is very easy because of the way they layed it out, it's also very easy to copy and paste tracks and adjust levels. It has plenty of great plugs in that can make your audio recording sound perfect and professional.
Pro Tools is obviously very expensive but it is worth buying, it's very easy to record and mix with. It has many great plug ins and you can record as many tracks as you want.