This is all great stuff... but for me, missionary doesn't just mean the girl lying on her back and the guy standing next to her. He should be lying on top of her to fuck her. For me, this gives the position an edge of male assertiveness and control rather than just being 'boring missionary position'.
For example, Clip 3...
http://www.sexintrusion.com/nasty_angel/25/sunporno4.htm
I gotta agree with you here, and this is what really makes the whole Mature/MILF thing work or not work for me. To see just another, bj/doggy/cowgirl/sidebyside/jerkoff scene gets to be boring and loses the intrigue of the mature vs young scenario. Give me a scene where the younger guy is on top, missionary style, in control and assertive, fucking the hell outta the older more mature woman, and wow, what a scene!
Yeah, yeah, I know we "need" to see pussy and clit shots, etc etc, but fucking is more then just a penis going in and out of a vagina. Some of the hottest scenes I've seen are man on top of woman and her arms and legs wrapped all around him, and they both fucking the hell outta each other. Sadly, this is where most porn today has become repititious and boring. The illusion of reality is nonexistent, traded off for camera angles and staged dialogues. No wonder I find myself watching more and more "classics".