I find the beta group to be really good for WakeMate. There is always the risk of new bugs as well as new features. If you're super super fussed about your data, I'd say stay away but it's rare to see a regression. Big issue for me was it wouldn't store my login so I had to re-authenticate every time I opened the app to go to bed, which at 5AM when you're getting up in 90 minutes is no fun at all. I think that went away in a recent nightly.