Feathers and which blades stay sharper, longer?

I keep hearing that Feathers are the sharpest, but do they hold their edge longer than other blades as well? Who'd be second?

B&B should have a ranking of blades in the Wiki, for sharpness and durability.

Also, I've seen two labels for Feathers, yellow and black. Is there a difference?

In my opinion, (and everyone has one, YMMV) I have 3 favorites< I know strange but true.
-Feather in my slant, (black right now because thats what I have)
-Iridium in my Chatsworth
-IP in my Futur
The Feather I feel is the sharpest of the 3 followed by the Iridium and the not nearly as sharp but great shaving IP.
For me just because a blade is real sharp doesn't make it the best. Unfortunately 2 of the 3 blades that make me say WOW are more expensive than most. There are many other blades I like and use on occasion:
7 O'Clock yellow
Kia
Bic
Astra
Sharp
Red Pack Persona
As far as longevity I really couldn't say because I typically change on the 3rd shave
There cheap enough, why risk it?

Kai and Astra SP are sharper longer than Feather for me...