It is a very beautiful country. The people are amazing! If you want a simpler life, this is a great place for it. Yerevan is very safe.
Of course, with any cross-cultural move, there are going to be adjustments. Having the right attitude will help! There's a learning curve and it could take a couple years!
You will do yourself a BIG favor by learning the language (either Armenian or Russian)! Pay a tutor, it's inexpensive and invaluable!
There are some things to adjust to and not a lot of American restaurants (there is a KFC that's decent though!) You will have to do without some things you like. For me, that is mostly in the food department.
If possible, it would be helpful if you came to Armenia for a couple months before making the big move. It will give you an idea of what you are getting into. The good and the bad.
Cheers!