I've started the GVT program 10 days ago (read more about GVT here) and I can tell you it's brutal. Everyday some of my muscles are sore...after chest/back days I have sore muscles, after leg days my legs are shaking and after arm/shoulder days I have problems lifting my glass waterbottle...good feeling ;)
I mesured my weigh before I started and it was 173.5 lbs (78,7 kg).
Now, after the first 10 days it's 175.9 lbs (79.8), a plus of 2.4 lbs (1.1 kg).
As I haven't changed my diet it should be pure muscle mass (propably a bit more as it's very likely that I've lost some body fat additionally).
Unfortunately I haven't done any other measurements than using the scale and the mirror (my main benchmark was and still is the look in the mirror).
Here's what I've done: