Getting feedback on your work is imperative. It doesn't mean you have to take all the advice you get, but if they're all saying the same thing, then you'd better do some serious thinking or re-thinking.
Why are critique groups important?
- They catch errors that you have overlooked.
- They bring their own experiences to the table.
- They have an overview of the entire thing, whereas you have been revising so much, you may have lost sight of the 'big picture'.
- They not only offer great suggestions, but support and commiseration during setbacks.