I BC'd 02/10/2010 and I am forever grateful that I did. My hair is back to be thick and heavenly! Ugh... I gush every time I think about it.
I transitioned for four months and got impatient... my advice to you is to protective style for as long as possible. Although you won't get the experience of getting to know your hair type and what it likes and what it doesn't like prior to your
BC you will be able to retain more length that way.
Make sure that you are keeping the hair underneath your sew in good and moisturized! Find some natural products that work for you... I love Say Yes to Carrots best product out there for me right now and it's at Target.
Assess your ends each time you take out your sew-ins because you don't want the relaxed ends to start to split and make their way up the shaft of the hair to the new growth.