Nope, Paint.NET is as far from the real paint as an image editor can get. The program feels like a clone of PS. It has some advantages over PS and some disadvantages. I just made this Planet from a Super Nova render I had laying around:

You can really go into detail with 3d imaging here. for ex:
source
The fact that PDN is open source gives it some serious advantages over PS, but I still miss my pen tool, burn tool, and dodge tool.
Here's one of my quick 3d renderings again:

Lulz, I don't think I'm ever going back to PS. /cancel d/l.