This is the second time we've been to Sinatra. It wasn't as good as the first, mostly because of the mediocre service.
The food was classic Italian, meaning the chicken parm was really really good, light crispy batter, perfectly cooked chicken, really nice sauce. My steak was above average. However, my side of eggplant was swimming in grease and tasteless. They fussed over us until we ordered, and then we were ignored. No one ever came to the table to ask if we were satisfied, and no one noticed that I only took a bite or two of it. That felt less than 4 star.
Bottom line, it's a Vegas upscale hotel restaurant. They don't have a famous chef, so they better deliver on service. It didn't happen.