the longer the ester on the testosterone is, the longer the steroid is active in your body, and the less actual test you get. This is because, for every 100mgs of testosterone cypionate you inject, only 69.90mgs of it is actually testosterone, the rest is the cypionate ester, which must be removed. On the other hand, with the propionate ester you´ll get 83.72mgs of Testosterone! The advantage to longer esters is that they need to be injected less frequently (test prop needs to be injected every other day while you can shoot test cyp once a week). The disadvantage to long estered steroids is that they contain less actual steroid. Anecdotally, however, most people who have tried differing esters on their various cycles agree: Testosterone Propionate causes the least side effects and the least bloating. For this reason, it´s often the testosterone of choice in cutting cycles. On a personal note, it´s the only form of testosterone I ever use, and it´s the only one most women will use, due to the previously mentioned factors (as well as it´s ability to clear your body quickly upon cessation in the case of side effects