Many of the things he mentions are not specific to ED.
He sure seems to be complicating the issue. I just finalized my lease and signed paperwork. I simply went down the form and, line item by line item, made sure it was correct according to my agreement with the sales guy (because the docs are actually done with the finance guy, as you know). There were a few things wrong. He fixed them. Not a big deal. Whether he was trying to slip one by me or not, it doesn't matter to me. They were fixed. We moved on. I'm happy with the final agreement.
What all of this has to do with ED, I don't know.
I went back to the beginning of the blog and followed it through to the "end." He ends by saying he decided to purchase a 550 instead of a 535. He never actually finishes the blog properly by relating his experience and telling us whether or not it lined up with the "analysis entry" you shared.
Current: 2015 i3 REx | Giga | Ionic Silver Metallic
2013 550i xDrive M Sport DHP | Jet Black | Venetian Beige | Dark Red Sycamore
2008 535xi Sport | Jet Black | Cream Beige | Burl Wood