I've been using Krita more recently because I want to move away from Photoshop, and so far I only have found very minor gripes with it that could probably be fixed very easily (except for the text tool).
1. There's no quick hotkey for moving or duplicating a selection, so you have to push more buttons to move things.
2. There's no way to quickly switch to a specific brush size, so you'll have to constantly fiddle with the stupid setting if you want to get a consistent line weight.
3. The selection tool creates holes in the selection if you do loops with it, while photoshop takes everything inside the outer boundaries. Photoshop's way is significantly more useful.
4. Eraser mode bugs out if you change brush color while eraser is enabled.
5. The text tool. Krita is pretty much useless for making decent looking text, there's just no way to make it look good, and the way the whole tool works is a pain in the shitter.
Krita has many things that Photoshop doesn't. I can easily see myself preferring Krita 100% of the time in the future.
Surprisingly it's the lack of silly shit like #1 that most commonly makes me go back to Photoshop. It just makes general editing stuff so much easier. People always underestimate the power of simple usability mechanics.