Addendum: I've reskimmed the two articles you linked, and can only think of you were holding it wrong :-) Several points, one I think I've already written about to you.
That trying out distros in whichever VM is almost useless for evaluating performance, because fucking VM! Also the used drivers are different. The only thing they are useful for may be testing the general installation process in advance, to see if anything wanted is missing, the defaults, if they are changeable to ones own preferences, or whatever.
The perceived slowness of the installer on bare metal. Again: Waddya talkin' äbbout?!
It all went by in a whoosh, and then it was ready to use. Maybe that W520 is crappy somehow? My install was on a machine from the same company, but different model.
M910q tiny with Kaby Lake Core i5-7500t, 32GB. Whoosh! Zoom! Motion blur!1!!
Needed internet connection, metered?!
I have flat rated and unlimited redundant fibre into my homes.
Who cares about Distrowatch? That is not a reliable indicator of popularity, because it can easily be manipulated.
Where was I? Uh... never mind...
