Totally agreed on the style thing, I left that out but meant to include it. Work should be the work agreed upon and any upgrades should be asked about first--one shouldn't just assume that someone wants something more than what they asked for.

I know there are plenty of artists where I love their chibi work or their cartoons but don't at all care for their realism despite it taking longer or being "worth more."

I didn't mean to come off as "well, even unfinished you should be happy he colored it" because that is definitely not how I feel--if someone wants a finished looking sketch and you do quickly done scribble coloring on it IMHO you've ruined the sketch if you don't finish. It's not a matter of "Oh, well you bought 2 hours of my time and I gave you 3, be happy" because the finished product is not what was agreed upon.