this may not be the answer you were looking for
but , true Aromasin is less harsh on cholesterol (meaning it will keep HDL more elevated) and it doesn't lower IGF levels as much as the other AI's.
Now why is this ?
Because its NOT as effective at lowering total Estrogen levels ! lol..
the more effective an AI is at actually lowering Estrogen, then the more effective it will be at crashing good cholesterol (HDL) and lowering IGF . thats because its Estrogen that binds to receptors on the liver and helps produce HDL and its estrogen that helps raise IGF levels.
so the answer of which AI is best is really dependent on the person and their situation . If you are super estgeon sensitive and your lean and prepping for a bodybuilding show and need to be super dry , then fuck your cholesterol or IGF , you need low levels of estrogen and Letro will be best . IF however your health markers are really important, and your running cycles for the whole goal of putting on size, yet your E sensitive and have to have at least some estrogen control, then using the weaker Aromasin is probably going to be best .