I've been playing Masters since day one! It's changed a lot and many things have improved, but still ways to go I think. It's a bit exhausting needing to get all these level cap increase items and right when I'm done, they introduce the next level cap so I have to do it all over again.... agh.
GO for me! It's just a lot of fun despite its issues. I love the thrill of getting shinies and 100% IVs. :D