tradeoffs
grave and day usually have less experienced people both on the floor and in surveillance. Swing has the sharper people but you have more action in the casino to blend in with. There is a luck element with whether you get the attention of the pit or surveillance. Whether they see you as a threat or not depends on many things as well as your act and how much time you've spent putting everyone at ease.
Personally I prefer some other action in the pit/casino. Anytime you are the only big action your odds of being caught go way up. But I don't want so much action that I can't move around or find close to heads up conditions. I like to play when the casino is doing the drops all around (money carts emptying slot machines and drop boxes).