Would be really interested to see some benchmarks comparing the performance of the Electron version and the previous version. Start-up time, time to perform common actions etc.
Personally I think it's a bit of a shame, since I seem to remember the previous version making use of the platform's native toolkits and widgets, e.g. WPF on Windows and Cocoa on Mac. I suspect the overall UX will now suffer. I guess it's easier to develop though, and works on Linux now?
Edit: Oh, there's still no build for Linux.
They do detail some of the reasoning (https://githubengineering.com/how-four-native-developers-wro...) behind this decision in the GitHub engineering blog and it looks like they've put a lot of work into this. But even the menu bar they've come up with (https://github.com/desktop/desktop/pull/991?) for Windows is obviously not native. The decision seems to boil down to (paraphrasing) "lots of people are doing web stuff" and "now we can reuse our code" ... which is fine, but again seemingly prioritises the development over the user experience.