I flew in an A320 and 757-200 on Friday and the 757-200 is by far my favorite. Series 5500 (from Tuesday's flight) has a short, but very deep, foot cutout for 2C and 2D. Series 5600 (from Friday) has a tall, but shallow, foot cutout for 2C and 2D. I don't think there's any easy way to tell what you're going to have before you step onboard...but with those seats you can't go wrong. Much extra legroom in any case, and no one to recline into you.

The 757-200 does have more ambient cabin space in F, too, and there was a marked difference versus the A320.