So far, I have mainly just used it to clean up my sketches. I have been having fun changing colors on things. These have been quite to time saver when working with clients. It is quick to change colors without doing all the work over and over. Here is a small sample of some interior options I did.
Original...

Slight two tone...

Change color of carpet...

I am working on one now that I painted a little in the background digitally (my first one with a big background- but it is to show the paint details you can't see on the rendering), but I have a friend coming over to give me a few more pointers.