In the 2020 model, the dedicated page buttons are gone. The old layout used split keys for the arrow keys, with (half) buttons for page up and page down on top of the left and right arrow keys.
The keyboard has seen a considerable revamp too. That little bit of extra headroom makes web pages more readable, staring at Slack less of a chore, and it means I can see my photos a little better when I edit them in Darktable. It's really nice, and I miss it every time I go back to the older model. Does half an inch really make that much difference? I want to say no, because I don't feel like it should, but it totally does. What does that mean for you? It adds a noticeable bit of extra screen real estate. Now there's a uniform, slim bezel all the way around, and this changes the screen aspect ratio to 16:10. Dell's InfinityEdge display has always had some of the thinnest bezels on the market, on three sides anyway: The bottom of previous models retained a larger bezel. The most obvious improvement in the 2020 edition is the larger screen. Open them up, though, and the pair are wildly different. The exterior design has remained the same for several years. I own a 2018 Dell XPS 13 Developer Edition, and setting up this latest model-which Dell has numbered the XPS 13 9300-it's nearly impossible to tell them apart when they're sitting next to each other with the lids closed.