In the same boat. It runs on mostly the same broad hardware (as I understand it leveraging much of the Android BSP work via libhybris). Obviously if you prefer Qt to Java/Dalvik it's a win, but the fact that it includes the Android runtime means that most app developers are going to target Android anyway.

It's sort of a wash from the perspective of open source. The SailfishOS core seems more open and "project-like" than AOSP, but just like with Google/GMS the core apps and user-facing bits are proprietary to Jolla. And being new, the ecosystem doesn't yet have good open source replacements you can find for Android.