So, when I started with sf about three months ago (or is it four already?), I had roughly 80 kg (180 cm).
I started out at Level 1.
Today, I'm at about 74 kg, and just finished L4D1, with 27 rounds. That's about as much as I got on Level 2. Pretty cool.
And today I noticed for the first time that the limiting factor wasn't strength, but endurance. My muscles could have continued, I just didn't have the air. And that's also pretty cool, as I'm usually better with endurance than with strength. So this means that I've definitely improved the latter.
Two days ago, I had pushed my L4D3 workout under 5 minutes, but I decided to go another week with L4, just to see how it worked out. And it works out just dandy.
So - this program is definitely damn cool. Thanks!
EDIT: And if this should be moved, feel free. :)