I also found that the nutstrip tie ins weren't straight. The right one isn't quite lined up with the frame rail, and while the holes in the tie in bracket matches the holes on the frame rail. The holes to bolt the bracket, and the bumper together don't quite line up.
I hate to say it, but I'm a little consurned with the way it mounts as far as downward pressure strength. I've been thinking of having a bracket made of square tube with a plate on the end to actually bolt the bumper to that will fit in the end of the frame rail (where the nutstrip would go) to tie it all in better. You would have to cut out the end of the rail for it to slide in, and then drill, and tap through the existing holes to the tie in brackets.
EDIT: On that note JCR pulled there 5X10 inclosed utility trailer full of goodies from Kalamazoo, MI to Flat Nasty off road park in Salem, MO with a Stage three, and a 31' tire hanging off it with no problems. So maybe it's nothing to worry about.