They are VERY IMPORTANT!
I have been VERY lucky so far with my beta readers. I got responses back from two of them already, and both have been very positive responses! They both loved it!
They also both pointed out minor mistakes that I fixed immediately. I am incredibly grateful that they caught these! As a writer, you tend to get too immersed in the world you’re creating. You can easily overlook small mistakes like that. Your editor might catch them, but even your editor can miss things.
I’m both excited and terrified to hear back from the others. I never thought handing my work over to someone else would be so hard, but I’m glad I did it.