Hi,
The control formula is for people who don't apply the relaxer as fast. That way you shouldn't have to deal with under or over processed areas. No I don't think one is better than the other. I have used both and I have never burned or underprocessed with neither.
After rinsing the relaxer, you use either the Affirm 5 n 1 or the Positive Link conditoner. After that, neutralize.
Hope this helps.
ETA- I am providing a link from the website that explains the difference between the two formulas. Just read under "benefits".
http://www.avlon.com/crmrelaxer.html