Oh, come on! 5 million?
I agree that a truer reflection is number of Unique Downloads = 2,309,459.
And it is a fact that Nexus counts every single download from a mod page, so if there are multiple versions and multiple optional files they are all added to the total. Anyone updating is counted as another download (I don't think it resets with a new version number and I don't think it is purely the number of separate PCs it's downloaded on).
For other mods, adding the patches for DLC are counted as separate downloads if they are on the same page and contribute to the total.
But 5 million due to sock accounts and spam downloading? I don't think so.
How many people play Skyrim on PC and how many of those use mods with a keyboard and mouse rather than a controller and how many of THOSE use SkyUI? I think that's the real statistic. Apparently, with a controller, the Vanilla interface is quicker than using SkyUI.
But I certainly use it as I have played TES since Daggerfall and Skyrim is unplayable without it.
As for the original question, my scripting skills are too limited to deliberately make use of SKSE, but the one I was working on this week uses some SKSE functions because what I wanted to do can not be done without it. I think!
~.~