I find with the guys I've worked with, adex seems to generally work consistently well. Everyone is unique though. Some do well with arom, some prefer letro.  I find that adex is strong but forgiving. If you wipe out too much estrogen, it's not hard to reverse the process. The only way you'll know is through experimenting. If you are new, I would probably start with adex. Make sure you get good adex. You may see it floating around the net being sold at "reseach" companies. The dosing from company to company, and even batch to batch, in the same company can vary, widely. So make sure you get your hands on good adex. Controling estrogen is a very important part of cycling, so I don't take risks to save $20 on something that might be weak, or worse, fake. I use either pharm grade, which can be very expensive or I'll use Geneza adex. Geneza seems to work just as well as pharm grade.