My wife and I were there for dinner when we visited in May. In my opinion, Cava de Cano is a "must". The food was very good, although my wife didn't care for parts of the first course, and you can't beat the experience. We were shocked as well that the bill was only like $80 US given everything we had.

A few other thoughts
-- They did not take credit cards when we were there so make sure you have Pesos.

-- The house wine was just "OK" in my opinion. At a $6 - $7 price point it's very drinkable but it was not one of my favorites while in Argentina.

-- Go hungry because you will leave beyond full. This is the case everywhere you go in Mendoza but it's especially true here because of the amount of food you get.

I know the Mendoza thread has other options for places to go, but if you'd like some other thoughts (especially if you're staying in Chacras) feel free to PM and I'd be happy to share.