I don't use the Samsung right now, I am using the WD Black, as I haven't moved over the 2TB (Windows) drive yet.
That being said, the 980 and 990 had firmware problems, but this was fixed a long time ago. If I remember correctly, it was burning out the drives a lot faster than expected. I patched mine before it was really an issue. Early buyers were not as lucky.
Clair Expedition 33 is getting a lot of good press saying it is the best game released in a while. I only played 10 minutes, I'm playing Lies of P right now.