I live about 45 min from Detroit, and I've been to all 3 of Detroit's casinos. I haven't been to the new Caesars Windsor though, so I can't tell you anything about there. Like you, I don't want to hassle with the exchange rate and the passport deal.
I've only been to Greektown once, and that was back in February this year. Dealer stands on all 17s, DAS, Resplit anything. Can't remember how many decks. However, from what I remember, the lower limit tables use Continuous Shuffle Machines, but I've heard that's not the case for the higher games. It's a bit of a dingy place, to be honest. Definitely the low man on Detroit's gambling totem pole. Hell, the place nearly had to file for bankruptcy earlier this year.
MotorCity's a pretty good place, but the Blackjack game is a little poor. Dealer hits S17, DAS, Resplit anything, and I think 6 deck shoes. However, penetration is piss poor at around 50%. These are for the low limit games, though. Can't tell you about higher limits. Nice atmosphere, not so nice blackjack.
MGM Grand's my favorite, both for the blackjack and the rest of the casino. Dealer hits S17, Resplit anything, DAS, 8 deck shoes for low limit games with pretty good penetration. I haven't played the high stakes tables. The dealers are a little incompetent, so keep an extra eye out for payout and hand total errors. There's also a couple of Double Exposure and Spanish 21 tables with total bullshit rules. If you get a meal there, the Palette buffet is pricey, but absolutely fantastic.
I'd say go with MGM Grand. I hope that helped.