I have used both, and syncthing is the most stable in my opinion. But you will get sync conflicts/ duplicates if you work on the same file
For working on markdown files you should additionally look into https://silverbullet.md , it's great ๐. It has offline mode. But it will also generate duplicates if you edit the same file offline
It works OK from the web page, but scrolling to the next item was a bit wonky for me. Using the swipe mode mis-fired when I was horisontally scrolling code. And double tapping didn't always work.
The UX feels smoother in News. You also get thumbnail images. And you can open the link to the source directly, which I prefer for some of my feeds. For me, the experience is smoother.