I switched a couple of months ago from Dev Edition as well. The biggest improvement for me? On macOS, I can control upgrades myself via homebrew. No more popup

I switched a couple of months ago from Dev Edition as well. The biggest improvement for me? On macOS, I can control upgrades myself via homebrew. No more popups every day begging me to update. It became really annoying that Dev Edition uses the same release cadence as Nightly, so you basically have a new update available all the time. And now vanilla Firefox doesn't even let you disable update checks.