Did this picture as a test.
Done ENTIRELY in Clip Studio Paint (Manga Studio).
From sketch, to inks, to flat colors, to shading, to background.

From my experience in using it now, I'd have to say that CSP makes Sai look like MS Paint LOL

Yeah, it has a looooot more features that Sai was missing, that I'd have to go to Photoshop for. And it seems a lot easier to draw in as well. It has a stabilizer like Sai does. But more brushes and tools to use.

Uh, I'd say Clip Studio Paint/Manga Studio is pretty damn fantastic actually. :O I'd suggest buying it when it's on sale though. Mine was $15 when it was on sale.

CSP is a great Sai alternative and I recommend it. It's like Sai meets Photoshop, but also with comic/manga-making capabilities like screentones and panels.

So far, I really like it and I might be switching over to it from Sai permanently now :3