They are actually really, really easy to install. All you have to do two perpendicular strips and then build out from there. So using my trusty tape measure and even trustier T-square I used one wall of the room to lay out the first row:
As you can see pretty much 9.5 inches away from the wall. Then I started the perpendicular row. And it really was perpendicular:
However, what I had forgotten was that in a fifth floor apartment in a pre-war building there is no such thing as a perfect 90 degree angle, but even with all of this I still find it hard to believe that the wall could be this crooked:
But I suppressed the worst of my OCD tendencies and instead of pitching a fit, I actually finished laying down the carpet. And if I may say so it looks pretty darn good.