I'm once again jumping in to the purchase of an RB67 and am wondering if the KL lenses are worth the extra cost versus the Sekor-C lenses? Is there a distinct improvement in sharpness and resolution when comparing prints/transparencies, or would it only be of concern to nitpickers? I'll probably get a Pro-SD body sinced they're not much more than a Pro-S at KEH. One thing that remains unclear to me is if the Pro-SD body requires an adapter for the KL lenses, or just the C. I've heard it can use all the KL lenses w/o adapter, while others have said only the 500mm and 75mm shift lenses work without it. Thanks for the help!