I've used niether, but have read about both. The main criticism I remember of this type of use of proviron was that allthough it binds to SHBG, it also competes for androgen receptors in skeletal muscle. Wich is a catch 22, since many or the AR's would be "wasted" on the much weaker proviron, wich may defeat its purpose.
I've only heard the anecdotal accounts on Activate, and know very little of its actual SHBG binding affinity.
So in other words.... I dont know...... (Mattris)