RQ,
Your category images are SUPER BANGIN'. So clear, a break rotor could come and hit me on the head right from the screen!
Those are very much like the ones I use not for categories but for product images - I use Knockout and Photoshop to make, what do you call 'em, PhotoObjects. Yeah, that's it. You have nice Photoobjects!
Were even these run through this mod? If so, I'd have to say the image quality is just about as perfect you can get on those.