I stayed at New York - New York and went to a trade show at the convention center. It was 100 degrees out and the monorail was nicer than walking and cheaper than a taxi. But if you're staying anywhere near the MGM, NY-NY, Excalibur, etc., you have to wander through the maze that is the MGM Grand to get to the monorail station. And when you get to the convention center, it's still a hike to the convention center's north halls. I like the monorail, but I wish they had made it a little more convenient. And if you're trying to get down to Mandalay Bay or Luxor, you're out of luck because the MGM is as far south as it goes.
It went where I needed to go and the A/C was working so I'm a fan. But they could have done so much better.