Native pdf reader vs drawboard pdf

[Azurus]

I am a medical student. I like to annotate my pdf files using the surface pen on my sp3 which I just received two days ago.
I tried using the native pdf reader of Microsoft to annotate. It works well but all of a sudden it crashes and restarts, not saving any of my annotations. I came along an app called drawboard pdf. It looks like a premium app. Tried it for free for a while. I don't know if I should buy it or not. Its for 10 bucks. Is it worth buying ? Or will the pdf reader crashing stop ?