Epi is an anabolic compound with low androgenic properties, it is great for growth and the strength gains are hand in hand with the added size. TR3ST is far more androgenic than EPI, so for strength gains specifically I would have to tilt my hat to the TR3ST. The compound with the higher androgen ratio is always going to produce the most strength. The androgens actually make the muscle fire off with more efficiency and hence more strength is realized.