1. How easy it is to add content. Google have removed alot of stuff that was unnecessary to 95% of users, things like exclusive buttons for horizontal lines, Apps Script and +1. It has been replaced with ....simplicity. e.g.
How to Insert a Google Presentation/Slides.
Classic Google Sites (left) New (right)
2. How easy it is to 'manage the site layout'.
The Classic Google Sites has an entire menu for managing the Site Layout. To do something like nest one page under another, you have to click on at least 5 buttons for each page....the same task is completed with a 'drag and drop' approach in the new Google Sites.
Changing the page layout and 'nesting' menu headers in the new Google Sites.
3. Sharing, Saving and Publishing. Anyone who has used other Google Apps before will find this familiar. No 'Save' button appears (like the old Sites) instead, content is saved as it is created and live collaboration is in place. Sharing is also not buried 17 levels deep, but right in your face, on the main page.
4. Mobile Friendly. Though the focus seems to have been on creating Google Sites that looked great on Mobile devices, I also believe that the new Google Sites will be very 'tablet friendly' and could imagine creating an entire site, from start to finish, on a tablet.
5. AI. Alot of the 'fiddly' annoying things have gone with this update. Stuff like positioning multiple pictures (automatically done) changing layout (drag'n'drop) and making text on images readable (font automatically changes when images are inserted) Intuitive is the word that kept coming to mind! It is only a little thing, but I am also loving accessing and creating Sites through Google Drive.
As Google Sites is still in a pilot mode, I am assuming the following will be taken care of before launch;
1. Way more fonts and themes - currently a small handful
2. Ability to see and edit the HTML of a page - for when the theme just doesn't work.
3. Inserting embed codes (possibly the only 'gadget' from the old Sites I will miss if it does not return)
4. The Search bar in the header - acts as a search for your Site.
5. More options to customize the header - especially changing the height of the header!
The new Google Sites will not be the go-to tool to create a complex website for a large business (or school) due to its (current) lack of customisation. It will however be a simplified way for any teacher to create a quick website in the same amount of time it takes to create a Google Presentation.