Maybe. It would all depend on a few things. If I was left unsatisfied due to his/her lack of attention and they the things that needed to be corrected were within their ability to correct then yes I would.
If it was outside of their ability to control such as health related issues that were causing it then I would attempt to work around them before actually throwing the towel in.

I think it depends on the person to be honest. I've broken up with someone who was very small & not satisfying. I didn't really have any feelings for him, so it was pretty easy to let him go. Now, if I had feelings or loved the guy, I'd stick with him. So, I guess it depends.