Well... what I can say is that retaining length for me has ALOT to do with the frequency of washing my hair. I neglected to wash my hair in the time frame that I was used to and lo and behold...note siggy pics.
Heat is my hair's friend too. I have to deep condition during every wash. I rollerset my hair to dry. I know for a fact that airdrying breaks my hair off. What I'm going to attempt to do is dry my hair in big braids with rollers just on the ends. Perhaps that will cut down on the drying time. I'm in the experimenting stage right now.