I just started wonderslim today and will let you know. I've tried Medifast and I just couldn't get past the taste. Also, I never got past the hunger phase. Maybe it was just me, but even after a week I was still starving (yeah, ate all the meals as directed). Plus with Medifast you don't do fruit and I really missed fruit.
So far I really, really like the taste of the Wonderslim products (compared to Medifast) and I think the plan is very doable for me--it allows limited starch and fruit. I'm done the first day and, strangely, am not hungry and I feel satisfied. I'm actually feeling optimistic. I look forward to seeing what others think...