I have tried and tested Letro in every aspect of the drug, yes it increases testosterone levels running a low dose and can be used as a PCT, however on a hard cycle the protocol 3 that is advised is what works...
Anyway, I find 0 difference between 1mg of Letro and 2.5mg it does nothing more for estrogen aid after 1mg pd, for me anyway. The only difference I experienced was feeling very sick, extremely painful joints that I couldn't even stand longer than 5 minutes without my knees wanting to give in, and libido took months to correct.
0.25mg on cycle for gyno prevention started 2 weeks prior to the cycle is the best way to handle it, this way if you start to develop gyno it isn't due to the plasma level of the drug being stable but not enough estrogen control and you can increase it from there. However for 90% of people that is more than enough and works and will not cause terrible side effects.
However if you have the cash Adex is so much better in all ways...
"Whether You Think You Can or Can't, You're Right"--Henry Ford