well i have never tried th SF shakes, but i will warn you of one things, check to see if they have sugar alcohol in them, for me i have been doing LC for 4 wks and have not lost a lb. which i thought was really weird because i did the LC things about five years ago and lost 15 in 2 months. i read something on this site on tuesday about some people being sensitive to sugar alcohols and that you wont lose. since tuesday i have not had any sugar alcohol and have lost 3 lbs. sugar alcohol is found in most LC candy bars, atkin bars, and i think shakes. some people are not sensitive and they lose weight. i had to figure it out the hard way