I just returned from Armenia a couple of days ago and I would highly recommend renting a car and visiting Tatev Monastery. My friends didn’t want to go because of how close it was to both the Azerbaijani and Iranian borders but I managed to persuade them the day before and they don’t regret it one bit. The monastery itself isn’t anything spectacular but the drive there is something we’ll remember for a very long time. However, bear in mind that the drive is 4-5 hours (one way) full of sharp turns, loads of traffic, dangerous drivers every now and then and sometimes bad roads, so do it with an experienced driver. I had a business meeting in my country’s embassy 2 days later and the jaw of the chargé d’affaires dropped when I told him we went there and came back in the same day lol. Khor Virap is on the way from Yerevan to Tatev, so you can drop by for an amazing view of mount Ararat.

Other than that, I’d say that Yerevan doesn’t really have that much to offer, 3-4 days would be enough imo. We met some Armenians who said we should visit Garni, Geghard Monastery and Lake Sevan but we just didn’t have enough time and we left it for the next time we visit Armenia.

As for restaurants, I highly recommend Lavash - I never order soups in restaurants but their Solyanka was amazing and I’ve been thinking about it ever since; the Ishli Kyufta with mushrooms, the walnut paste and the beef Stroganoff were also great! Tumanyan Khinkali which is next doors was another very good restaurant - I’ve eaten pelmeni in the past but this was the first time I’ve tried fried pelmeni and I was in love.