I've been off the NG 800 about a year but I've never seen that 13 kt restriction in my limitations sections, and I've never heard that Boeing recommends landing in a crab above 13kts.
I've landed wing-low in 25kts of x-wind. My experience is that if you touch down in a crab you'll get one hell of a shimmy and shake and the airplane will be cocked off about 3 degrees into the wind on taxi in. Looks weird. You'll also scrub the tires up pretty good.