I was there for the Triangulum Event and it was awesome, the place is like made for the events!
Other than this the temple itself deserves a visit or two. Recommended!
It's an amazing place to visit in Armenia. 3 places that amuse everyone who sees them, two in range of half a mile, and the third in 8 miles. Garni temple, Simphony of Stones, and Gegard cave monastery.