One thing that should be clarified is that 600mg/wk of Test Enth is a safe dosage--period.
There have been multiple studies that have used this dosage and have had zero instances of side effects. I would even go so far as to guess that this may be why this particular study chose 600mg/wk as their top dosage: they knew it was safe, but didn't know if higher dosages would be.
Now, that's what the studies say...if anyone knows firsthand of anyone that's taken 600mg/wk for a first cycle and grown nice B-cup breasts, I'd love to read it.