Yep, I gained as well. I'd come out of each cycle weighing slightly more than each time, lol. But, I've started using it for that purpose, to really put on muscle. What I did this time, though was pyramid my calorie intake along w/STS. So at both ends of the pyramid I was eating less, yet in the middle (M2,3,2), I ate slightly more. This helped me to fuel my body enough during the muscle building phases, to take full advantage...yet also take advantage of the cardio aspect of M1 to help shed fat.
The food aspect is what really turned the STS pyramid into a "bulk/cut" scenario, & helped "reveal" the muscle a bit more than if I'd just ate regular, or stopped at M3...