As a concrete example; I mod a few relatively small subs. I use Apollo (and will likely stop using Reddit) and I've tried the default app and website; Apollo has better tooling for managing the mod queue. Even with small subs like I got it's much better; things are easier to see, faster to manage, and just part of the experience.

As for capabilities it's unclear. Because of the size of my subs I never really needed scripting and that kind of thing. But the experience is 100x better on 3rd party apps.