Having said that, the idea of ACES is to attract customers who are not day-trip slots players - the old Atlantic City mainstay and the target of the Pennsylvania casinos. The Borgata, Harrah's, and Caesars are trying to be destination resorts in the Las Vegas mold.
Yup; ACES is their attempt to compete harder in the NYC market, which is a huge potential market if they can break into it. Until ACES, there just hasn't been a good reason for gamblers to go to AC over Vegas or Connecticut despite its apparent geographic proximity to New York.
Flying NYC to Atlantic City is ludicrous--no non-stop flights, and 1- or 2-stop flights are over $400. Flying to Vegas for the weekend can be done $300 round-trip non-stop. Flight times are the same. And Vegas is where the money is--the Borgata, Caesars, and Harrahs Atlantic City just don't measure up to the Venetian, Wynn, Bellagio, etc in Las Vegas. Caesars and Harrahs are two of Atlantic City's top casinos. There are Caesars and Harrahs in Las Vegas, too, but they're second-tier casinos there. The Borgata is very nice, but it's no Bellagio. There's absolutely no transit-based reason to choose Atlantic City over Vegas if you're flying. (Even hating time zones doesn't influence your decision, since time is completely irrelevant in Vegas.)
Taking the train (pre-ACES) NYC to Atlantic City is also ludicrous--requires a transfer in Philadelphia that isn't designed as a connection and takes about four hours each way all-together (half of which is on the NJT-ACL, hardly classy). Taking the train to Foxwoods/Mohegan is faster, cheaper, and more comfortable--a connecting bus meets the train in New London and goes straight to the casinos (and high rollers can probably arrange for limo services to do the same). And Foxwoods and Mohegan are huge, larger than anything in Vegas even, and utterly dwarfing the Borgata. So there's also absolutely no transit-based reason to choose Atlantic City over Connecticut if you're taking the train.
And Google gives driving times from 10010 to both the Borgata and Foxwoods as two hours and thirty minutes, so the same arguments apply as with pre-ACES trains unless you live on the New Jersey side of New York City.
Atlantic City stands to gain a lot of New Yorkers if they can make ACES work!