From experience, mast is good for the kick and more aggression and strength in the gym. Didnt notice hardening but was 12% bodyfat.
But it gave me anxiety issues at 400mg, which i believe i could have avoided with more frequent smaller injections (was pinning 200mg 2x per week).
Weird feeling, i simply couldnt calm down. As if adrenaline was being pumped constantly through my body. Really anxious and nervous, would start the next day after injection and would dissipate prior to next injection.
Hence my reasoning to go ed with tren a. Lower peaks but same effective dosage,