I have used both. Both seperately and stacked.
Used Androsterone up to 1200 mg ED. Up to 900 mg I got good strength and endurance gains,but was also quite lethargic.
With 1200 mg I started to get hairloss, some prostatit sensation so I scaled the dosage back to 900 mg.
I don't get the same positive effects with epiandro only (strength, endurance etc) but not the bad ones either (lethargy).
I like the stack of them, but I havn't find my real sweet spot for them yet. But I think around 400 mg Androsterone and 500 mg Epiandro could be a good starting point.