Updating Unity or not when working on a project?

Hi guys, it's my first post here. I'm new with Unity, I've been working on it only since few months, a little before Unity 5 was released.

I remember that, when I was still using Unity 4 for a very simple project, and I updated it to Unity 5, when I opened that project back basically everything in the scene was removed, and I had to rebuilt it back. Well, it was no big deal since it was just a trial, but right now I'm starting to work on a bigger project. The minor updates I did since now (like, from Unity 5.1 to 5.2, etc...) didn't do any harm to the trial games I was making, but what I was wondering: now that I'm working on something that I absolutely don't want to suddenly be deleted or messed up, is it a good practice to install new updates of the engine? Or should I install only the minor ones and ignore an eventual Unity 6?

Thank you in advance for your replies!