Wine selection - excellent, service - excellent, ambiance, not so much. Double Helix is in the middle of the Palazzo Shoppes so you really are sitting in a shopping mall.
We order a flight of reds and a flight of whites. We really did not care for one of the reds and told the waiter as much. When he brought the check, he brought a glass of another red that was excellent. He told us that he couldn't let us leave without a wine that we'd enjoyed so he gets 5 stars but the bar itself only gets 3. The Wine Cellar at the Rio beats Double Helix, hands down.