My experience with S4 was a great one. Positives were crazy vascularity and muscle hardening as well as great strength/endurance (Staked with GW). I started off at 50mg/day and didnt have any vision issues at all, not even the yellow/green tint everyone talks about. I crept up to 100mg/day and i still had no vision sides for the first couple of days then i noticed everything slightly green but nothing drastic and i barely noticed it. Night vision wasn't a problem either. The only sides i got at 100/mg a day is i felt a bit more "tired" than usual, Dont know how to explain it but it felt a bit like when you get low blood sugar. I think the best dosage spot is 50mg-70mg/day IMO. Overall S4 is awesome.