The sad fact in Argentina is over the past several years, the near guarantee of getting a decent piece of beef in any parrilla of the barrio has gone from the high 90% to the teens. This is a direct correlation with the change in most beef production to feedlot over the past decade. I'm not sure of the actual current stats, but it must be about 70%+. It is getting harder and harder to find a reliable good parrilla. Even the old San Telmo reliable excellent standard, La Brigada, is totally off my radar after my last meal there of "ok" meat and awful service.
Le Grill is a steak house that provides an atmosphere much better than most parrillas - more like one might expect in a fine restaurant (which is not parrilla standard). I've been there several times, with typically decent to excellent food ... until last week. Two of the three of us decided to try the dry aged beef. I've never had grassfed beef as "dry aged" but we paid a nice premium for it, and mine arrived overdone and not very tender. The third ordered the rack of lamb, which he thought delicious.
I wouldn't hesitate to return, but I would not suggest that one pay a premium for the dry aged beef. The two of us that did (and one is a native and great home parrillero) ordered different cuts, and were both quite disappointed in the meat.
Service was fine.