I just started Simplefit week 9. As I've mentioned elsewhere I'm pretty satisfied with the program and my progression thus far. I'm 25, 5'11" and at the start of Simplefit I weighed 157 lbs. In the first few weeks I actually lost 5 lbs (I'm about 152 in the second picture below) but after adjusting my diet I'm now up to 162. At my peak of fitness a few years ago, when I pumped iron and worked a physically demanding job, I weighed 180, although then my legs were bigger too.
My goal? 175 lbs (if my girlfriend allows it, she likes me skinny for some reason). I think that's do-able, although maybe not with Simplefit. However, my strength, endurance and cardio gains have been so good that I'm sticking with the program to see if I can tough it through Level 8. Then I'll move on to something else. (Hopefully a more advanced bodyweight routine.)
More than anything, I'm shocked how quickly I've increased my pull-up max. In the 9 D1s I've done so far I've gone from 19 to 56 (holy shit!) unassisted pull-ups in 20 minutes!
Apologies for the MySpace-style photos, I don't have a real camera.
Image below: week 2 (L2) -> week 5 (L3) -> week 9 (L4)