Obviously, no one probably does their sprite work in the built in editor. But making making small adjustments and changes, or creating debug art is quite useful.
BUT... there is no hot color picker hotkey, only a toggle. If I am making quick changes, I usually want to grab a color, but as it stands you have to "i" "click pick" "n"
Thats alot more work than "alt +click" then back to painting.
For small projects, it isn't too hard to keep photoshop or aseprite open but that adds a small workflow penalty.