Just to be clear for everyone, the issues were with the Samsung 840 Evo. The 850 Evo have no reported issues.
Also. here is a site I keep bookmarked for reference on what the current best SSD's are:
https://www.hardware-revolution.com/best-sdd-solid-state-drive-september-2015/
John, there was a thread about it. Samsung ackowledged the problem. The fix was a pain in the ass on Mac. I retired and replaced mine. Apparently, experiences vary, but as Remo the mob boss said in "Casino"- "why take a chance?"