Everyones different. But if you've run Tren without problems, I think Mast should be fine. I LOVE it. I like it better than Test even, though I havent run Mast seperately, so maybe I just like the combination.
Hair's is ok, I get a BIT thinner over time, but it grows back after the cycle. Prostate is fine, no pain, or trouble urinating. I think my prostate is actually better with Masteron than Test alone. No acne to speak of, but I shower at least 2x a day and tan for 6 minutes a couple times a week, this really helps.
If I may suggest something, for Mast E, try less than the 500 per week a lot of people use. I get great results at 250-300 a week of Mast E and a little test. Depends on your goals, but that "little" amount has been great for me for strength and hardness and just feelin' good!