After some really bad rusting on my Benchmade 51 due to the D2, living in a humid climate, handling it for hours a day, simply rubbing it with gun oil every couple months, and not having anything like Tuf Cloth, I've become extremely paranoid with satin finishes. Whenever I touch them or I see a slight discoloration from use or anything, it drives me crazy until I wipe it down with silicone cloth. Just feeling the raw metal type texture kind of makes me cringe. I pretty much have to buy everything stonewashed or coated, or stonewash it myself, because that makes it feel almost lubricated and the discoloration isn't as bad. I simply cannot handle a knife with satin finish. I own one, but I rarely carry it.
Other than that, the only thing that bugs me is blades rubbing on the liners. I can tolerate off center blades, a tiny bit of bladeplay, lint/dust in the inside, pocket clip wiggle, etc.