Good on you for saving the old C: drive
+1 for a Sandra report. I have had no issues with Windows 10 on 4-5 custom builds or on an HP Z820 12 core($1100 from eBay).
More thoughts on the new SSD:
If you just cloned from the old C: and upgraded the OS afterwards, it might be worth running optimization software(Samsung SSD's include Samsung Magician. After running it to optimize, uninstall it as it is no longer needed and might make your USB drives disappear like it did for me(once it was removed, the USB drives all showed up fine)