I've spent some time building test automation with Android Studio and it's been pretty solid overall. The Espresso framework does most of what I need for UI testing, though I had to write a lot of custom wait logic because the default synchronization does not cut it for complex apps. The Layout Inspector is very helpful when tests randomly break, as I can see exactly what's happening in the view hierarchy. My biggest headache is honestly the build times, waiting 3 to 4 minutes just to run a single test gets tiring fast when I'm trying to debug something.

A powerful tool that supports a lot of features like Kotlin and integrated tools but it requires a high end PC to run it.