Which Las Vegas hotel has a better lazy river? MGM Grand or Mandalay Bay?

I've been to the Lazy River at MGM and loved it. Has anyone been on the lazy river at both Mandalay Bay and MGM Grand?Which Las Vegas hotel has a better lazy river? MGM Grand or Mandalay Bay?
Mandalay Bay has the best pools on the entire strip.Which Las Vegas hotel has a better lazy river? MGM Grand or Mandalay Bay?
I've never been to the one at Mandalay Bay but the Hard Rock Hotel has a similar thing. For my money, that's the best one.