I also second Maia Sepp - she's fantastic for many things, and I suspect adapts to whoever she's reading for. With me, she's great for picking up internal inconsistencies and pushing me to get deeper into the character's emotions, and not afraid to tell me when it just doesn't work. Love working with her.
ETA - for me, Maia feels more like a mini developmental edit - lots of inline comments and a covering report. I have used another paid beta reader who had a much lighter touch (and lighter cost) which was also really useful, but a very different approach. So, I guess it depends on what you are looking to get out of the process, too.
Maia's prices are expensive for a beta reader but cheap for a developmental editor. What kind of comments does she give?
Sounds interesting, but I'd certainly try to sample edit. I've had so much disappointment with expensive beta readers that lately I've only chosen cheaper beta readers (and still had some disappointments).
I am sure Maia does samples, so you do get to try before you buy. Yes, her prices are high for beta reading, but every time I've used her not only has the book been much better, I have also learned more as a writer which I can put in to the next book.
Examples of some of the things she picks up on:
- major plot points - do they work, where they fall flat, where more foreshadowing is needed
- inconsistencies in plot - which can be niggling little things like making sure the time taken to travel is consistent
- character development - if it's consistent, and where more backstory / emotion would be helpful
- and also, where she sees it, some editing matters like weird phrasing / words, missing words, typos, etc.
I just checked my last MS that she read for me and it had over 500 inline comments on the Word document (including quite a few frustrating minor typos) plus a covering report of about 8 sides of A4.
All this might be old hat to you, and you may not need it, or even find it useful - everyone's different.
I consider myself still at the start of my writing career, and I'm also one of those people who learns best by doing, so this kind of personal feedback is incredibly helpful for me.