the Roush are great, easy install, and look beter as well. they even have the timing marks that ford forgot about on the balancer.
my U/D pillies gave a getter SOTP feel than my O/R H pipe, even though they are advertised at about the same gain.
Steeda gives you a new bolt to replace a stud, but Roush tells you to trim the stud. after careful consideration, i chose to trim the stud. it will make it a little better down the line when you need to do maintenence, like replace the alternator.
i will be finishing up my write up on the pullies soon. i will post a link when finished. the Roush instructions are very easy to follow, and give color pictures as well.