Break the rules, but break them effectively.

Writers get told to follow the rules. Rules in this case being proven guidelines of what works and what doesn't for an unsuspecting reader. I've come to learn that they are rather helpful, especially for new writers. Once you are acquainted with them and have successfully written your book(s) applying the rules, you are ready to break them.
To be clear, I'm not talking about grammar like syntax or tense. If they are used wrongly, it could be a rather odd read, dialogue being the exception. If the character isn't a native English speaker, it should reflect, as well as when a character isn't as well educated.
No, I'm talking about the more advanced writing, about the author who tries to experiment with different ideas and styles. As many of you know, my short stories are in second person point of view, which many writers said is a big no no. I shrugged and let the public -- the readers -- decide. Not one complaint in over 4k sales.
Others will say head hopping should be avoided. Why? If done well, you won't even notice it. I know of a bloke who experiments with punctuation, or better the lack of it -- mainly the speech marks. That's brave and difficult to pull off. Haven't read the book yet, but will try a sample to see if it works for me. Readers have complained. A lot. Probably a sign that he didn't pull it off well enough. Or maybe they weren't open to it.
My opinion: if you break the rules, be consistent throughout the book. It should be easy to adapt to and made enjoyable. 
I had a conversation with one of my Twitter friends, who said he's a minimalist when using commas. When I read a sample of one of his books, the absence of commas before names in direct speech irritated me, so much, that I'm confident I wouldn't be able to read one of his books. Nothing to do with the quality, but I just hate this particular comma not being where it belongs. I know you can see from the sentence if it needs a comma or not. (Age old: 'Let's eat grandma' vs. 'Let's eat, grandma'), but if you use it in one case and not so in another, it would make an inconsistent use. To me, that is. But what if other readers think the same? Is it really worth it to compromise this little comma?
But if breaking the rules means being inconsistent, then it might be the wrong way of breaking them. Those readers who don't know that the author intentionally omitted them, will think s/he doesn't know any better and might dismiss the author as unprofessional.

What do you think as a reader, do you mind?
For authors: Did you break rules?
Why did you do it?
Did you receive complaints, praise?
Would you do it again?