Like I said, I don't want a scrap & I wasn't dissing anyone. I have flown Nexstars several times a week since they first appeared & I just haven't seen an airframe-related take-off difficulty that could be attributed to the anti-spin devices. Warped wings, yes, excessive side thrust, yes, & a bunch of landing gear & runway issues as well --- but not the add-on wing cuffs.

It might help if you described how one could be high on the wing & the other low on the wing. They are pre-shaped to fit tightly against the wing in a specific attitude, and they are graphically marked for simple spanwise alignment. Obviously virtually any defect is possible in a manufactured product -- I'm missing some information here that is clearly of significance. Do you have a pic? -- that would help.