Probably a 3.5 with the disclaimer that I came here for a work dinner, so we had a large (30-ish) party in one of the private rooms upstairs.
Our dinner started off with passed appetizers, which I'd rate "ok". In particular the meatballs were terribly dry and rubbery. An open bar with attentive service helped though..
Our group had a limited menu to pick from so I'm keeping that in mind because I'm sure there are more interesting/creative dishes available than what we had to pick from. My starter was a Caesar salad which was "ok" - it was unevenly dressed (the dressing was really thick and parts of the salad had none while other areas were all dressing). For a main, I went with the roasted chicken which was really, really good - crisp skin, moist meat and good seasoning. It's hard to make chicken for a group but Aria nailed it. Dessert was a vanilla cheesecake which was "meh" for me - nothing special but certainly not bad.
Our servers were really nice but probably could have used another pair of hands to keep drinks refilled and plates cleared.
I think Aria is probably best for a party of 6 or less and I'd happily return to check them out in that context.