I've gone to this grill's older sibling, Buenos Aires Pizzaria, multiple times. The empanadas are great, the gnocchi fresh, and the pizzas delicious. The service can sometimes be slow, but when you go to a Latin restaurant, you can't expect Germanic precision.
The Buenos Aires Grill, at 2191 Arapahoe St., is beautiful. The ambiance is elegant and there is a gorgeous courtyard. When we arrived at 6:30 pm, the maitre'd gave us an inexplicable caution about making a reservation next time. Inexplicable because the only seating that was mostly full was the courtyard seating. Granted, it was a gorgeous evening and we preferred to sit out there, but it wasn't a requirement. Later in the evening the inside tables were mostly full, but goodness gracious, no need to lecture.
Anyway, I really shouldn't have gone to what is, in essence, a steakhouse when I am trying to eat vegetarian. (I just feel like I shouldn't be eating the flesh of animals at the moment, no biggie.) The steaks were very tempting. But, I managed to resist, mainly through the enticement of a delicious sounding "Butternut squash and walnut ravioli in a cream Roma sauce." It was delicious. I finished with thier divine dulce de leche helado, which I had eaten before at the pizzaria, and made all my dinner companions jealous. I'd describe what my dinner companions ate, but I didn't hear (or taste) what salad they shared and they got the ravioli the same as I did. Yes, we all had the same dish. Sad, eh?
The prices were ok, commensurate with the caliber of the the food and the ambiance. The service was decent as well. My water was filled promptly (avoiding one of my pet peeves). The empty plates were bussed in a reasonable amount of time.
I might prefer the pizzaria slightly, since it's more affordable, but the grill is perfect for a special night. I recommend it and definitely plan to return.