It's great for distributing to wider group of external beta users but sucks for internal testing, especially if you want an API that can be used by a CI system.

At my workplace we use TestFlight integrated with Jenkins. We commit to the repo, Jenkins builds the APK, and submits to TestFlight. Then our QA team can pull the latest build onto their device and test, and we get crash reports if things go south. That tight loop is not as easy with the Play beta testing.