i've personally used a couple of their blends and i can tell you from my own expereince that GP is one of the top of the game when it comes to brewing gear and the new blends are no exception. with newer solvents, gear consentrations can be made much higher and remain stable. thats why you may see some brands like GP come out with these blends or high dose tests. even without these solvents, some esters can be safely made at higher doses and remain stable. i've personally made tren in the past, dosed at 160mg/ml and had little problem keeping it stable. the main concern with high mg per ML is the potential for pain due to placing such a high level of hormone into one site. i can personally attest, that these blends are, at least for me, no more painful than any other inject. i've read the boards and it seems that most people would agree with me. if you did find yourself sensitive to high levels of mg per ml, you can always add a small amount of sterile oil to each barrel you inject, or add another pain free aas to cut it down a little.