Just FYI, my year old EVO840 250GB scores me 7.9 on the disk thing on WEI.
I do have a 1TB SATA3 HDD, and I do believe that also matters.
WEI scores aren't all about speed. There's a bunch of different aspects that come in effect.
Also, I think the decision to drop WEI for Windows 8.1 was more due to the woeful lack of horsepower portable W8 devices suffer from in comparison to proper PCs, and I do believe it may have been hurting sales for Microsoft.
After all, who wants to pay 400 bucks for a netbook with 3.4 on WEI?
Not that most people care about that, but WEI really was created to create a kind of "relative" benchmark to guide consumers in their purchases. Techies know WEI is totally irrelevant.