I agree with @BigDamn about more explanations behind the tiers, maybe right on the original post itself.
The number of tiers is ok. But I would rename them to:
"Bomb" tier (D)
"Won't catch fire" tier (C)
Single GPU tier (B)
Dual GPU tier (A)
Mining Tier (S)
I wouldn't weigh in value (since this is a regional thing). Warranties from reputable brands do have some weight imo, but I know the list put emphasis on the unit itself. If you did want to start weighing in noise I could see lambda ratings being added to the entries themselves, or mention that there's a zero fan mode. But that may complicate it a tad, I'm definitely in favor of keeping it simple so people don't blow their system up.