My wife has several different types of orgasms. Her most powerful ( body shaking / mind-blowing ) is her clitoral orgasm. For her this orgasm is continuous for 3-5 minutes, but it may take a half hour of licking her pussy to get her to that point.
After a clit orgasm, she will have other types of orgasm from penetration, but these are not nearly as powerful. If a guy does not give her a clitoral orgasm to start, just getting fucked it doesn't do much for her.
She much prefers having her deep spot filled and not her cervix pounded. If the guy is fairly large he needs to be careful and at just the right angle and avoid hitting her cervix straight on and get into her deep spot. Her deep spot gives her waves of pleasure. Most women I have been with find hitting the cervix directly quite painful, but love it when my head pops under/past the cervix into their deep spot.
Smaller guys (less than 8") seem to work better for giving her G-spot/squirting orgasms or anal orgasms. Bigger guys (8"+) give her deep spot orgasms. To her even the most fit and hung guys are worthless, unless they can give her a clitoral orgasm to start things off.