Masteron is great. I personally need to run it around 800mg/week to really see and feel the effects, whereas I know many can achieve this at half that dose. I have always stacked it with test, and have run it both higher and lower than my test dose (I prefer the former). For me, I see ridiculous core definition, not much mass increase, increased vascularity, and predictable strength gains. My aggression and libido are both increased significantly compared to test alone. In terms of side effects: my already balding head is made worse by masteron, without a doubt. I also notice a change in the appearance and quality of my skin. Mast gives me a drier, duller quality to my skin, and can definitely aggravate any existing acne, and make the process of eliminating acne much harder.
A great compound all around, but in all honesty, not the most cost effective, as real masteron is not only hard to come by, but pretty expensive as well.