Even though I'm not a member of "the club",
I have been following all of these threads, so I have seen your pics already. Your aren't humped as much as my OEM blades for sure, but the hump is quite visible.
As far as the drag issue, let's think about it for a minute. If the deck is pitched 1/4" front to rear as most guys seem to do, that's over the length of an approximately 21" blade. That's a pretty shallow angle, and you can bet your hinnie that the grass blades will still be dragging the blade's bottom surface. Think about all the turbulence under the deck surrounding the grass blades as they are cut. Too, when the blades actually make contact with the grass blades they tend to bend over slightly before being cut off, which means that they spring back up enough in all probability to drag the bottom of that shallow pitched blade.