My primary beta reader has been my husband. He has a great personality and is extremely well read. He reads everything from Lee Child and Michael Connolly to David McCullough and Will Durant, plus sales books, books on religion, golf, and on and on. He's usually reading about 4 books at a time!!!
For my book, he has read each chapter as I have written it and critiqued the good and the not so good. I have found his editing to be quite excellent. The only unfortunate thing my story is derived from our experience where we live now so, naturally, he doesn't have complete objectivity. Therefore, I have passed the ms out to about 15 family and friends. Not all have checked back in but of those who have most really loved it (so they say) and a few say they can't wait for the next book in the series.
Be that as it may, I would love to have the good readers at AW have a shot whenever I qualify for this service. And I am quite happy to read in return, although some of these genres I know nothing about and have little affinity for. But I will take it seriously as I know, from my husband's contribution, what it takes to be an effective reader.