I just finished integrating the feedback for Flight from two beta readers who read the entire thing and six chapters from the writing group. They caught a lot of little things that I keep missing, which I'm eternally grateful for.
One thing I noticed is that everyone caught different things. Yes, there was pretty much a universally circled point when I wrote "the wore that ripped the land in half," but for the most part, they caught different missed words, confusing phrases, and other stupid little mistakes.
It really points out, that if you do the reader approach, get as many different people as you can. Everyone sees different things, their eyes slow down at different points, and they just pick up the wrong errors. I recommend it, if you can, I think I have a better chance because so many people are helping me.