If availability, money and time weren't an object, then Aromasin would be my first choice. Otherwise, going with Femara or Arimidex really doesn't make much difference. With proper diet and AAS cycling, I have seen that Femara and Arimidex are just as effective at countering estrogenic sides as aromasin. Bottom line: Everyone, except those with superior generics, should be using some type of aromatase inhibitor (either aromasin, femara, or arimidex) DURING an aromatizing (Testosterone-based) cycle. I have seen those with superior genetics and low BF% get away with using Nolvadex as their antiestrogen during a cycle. Everybody ahs to listen to their bodies and make the adjustments.