Sibir, a privately owned domestic Russian carrier, bought 70% of Armenian Airlines, and renamed the operation Armavia. They put in cash to improve planes and service and so on. You will likely get service that resembles one of the private Russian carriers -- bad, but that bad.

Is scheduling convenience more important to you than service, safety, and "peace of mind?" I would pick the more reputable carrier no matter how inconvenient the schedule -- but everyone's personal preferences and tradeoffs are different.

BTW, safety has little to do with where an airplane was made. I would feel much safer on an Ilyushin maintained and flown by BA than on a Boeing maintained and flown by Armavia.