Size - 10/10
Honestly, this is where X-factor shines. I put on 13 pounds in 50 days with almost ZERO CHANGE IN BODYFAT!! You can't say much more than that...can you? I did stack this is MassFX, but I feel that X-factor was more responsible for the size gains, and MassFX for the strength.
Strength - 7/10
While I feel that XF contributed to strength gains, I believe that stacked with MassFX it led to even greater ones. XF definitely increased strength though.
Side Effects - 8/10
DOMS are certainly prevelant. I don't mind them, but they are definitely there. I did not noticed any other side effects though. Sleep was not a problem and headaches NEVER HAPPNED!
Other Notes + Overall
Overall, this stuff plain old rocks. It really helps keep you lean while bulking. It exceeded all of my expectations and they were set quite high. Certainly worth the price. I will be running another cycle of this at some point. Probably cutting, to see how it works in that situation.
Before and After Pics
I think the major improvements are in my arms, shoulders and legs.