Hi
We don't know the difference, but I would be inclined to use the file with the 8-4-2016 date, as this is newer than the tweak.nl site.
ZyXEL need to sort out their source control and version numbers, I returned one because it kept crashing and everyone said theirs didn't, and it was because I was using a different version 7 of the firmware to everyone else's version 7, I assumed they were all the same as they would be for any other manufacturer.
Regards
Phil