The problem with the stu's coils, is you only get 1" of lift on the newer pats, you don't get any alignment parts as you do with the RRO, and its 3 times the price for just 4 coils. My RRO kit went on no issues, had it aligned without issue, and never had any problems with the quality of product. Yes, the stus will take trailering better, but will be jarring hard all other times while driving.
I have experienced both, and I would keep the fdII springs, if you don't have them, get them. and use the RRO kit.