This is a big update from development point of view.
So far one of the weak points of Unity was creating proper GUI system for a game. Using Canvas system you had to do most of the controls yourself or use buggy community controls. You were also given an option to buy a GUI system from the Asset Store or get a free one which, well also included bugs or missing features and you were dependent on third party - which is something I really hate.
I knew I just had to add a GUI system in order to make any editor style features like properties for objects and modules but I was just terrified by having to code it using Canvas. I remembered that Unity was working on a new system the last couple of years so I decided to check it out and...There comes UI Toolkit.
Using docs and the samples I was surprised how easy and fast it was to create any kind of GUI that I needed. It all layouts itself, no more Layout Groups, no more prefabs. You can use one style which applies to all elements, just like HTML/CSS - brilliant!
I'm never going back to old style GUI in Unity, long live UI Toolkit! If any of you reading this are Unity Devs and are still having doubts about migrating, wait no more! Good Luck.

Here is list of all the major changes:

• new UI system
• new tools UI
• added Tooltips
• added Radial Attractor object
• added Radial Repulsor object
• new color palette
• introduced properties with new objects
• fixed basketball texture bug
• additional sample tracks

Enjoy!