These are significantly different compounds.
1-andro/1-DHEA gets most of its effects from conversion to 1-androstenediol. It does not convert to estrogen, but I don't believe it converts to DHT either...this is a killer to the libido and really instigates lethargy.
Androsterone is a different beast...it's more androgenic, but not as anabolic, and converts highly to DHT. This is where hardening, libido, aggression, bloat reduction, etc are amazing.
There are a couple new androsterone products on the market and I heard there's a new transdermal version that should be out in the coming weeks...have a feeling it's going to be quite popular.
Androsterone was also in the well loved primordial performance Androhard product...
in reality, I would love to run a stack of 1-andro/4-andro and androsterone...I think that would be an awesome ride! maybe add some epiandro too