The park recently changed Rainbow Valley Trail, which I thought was the best in the park because it actually climbed into the hills. I haven't been on it since, but I know that they rerouted it around
the hills (see here
The views are probably still nice, but there's hardly any elevation gain, if that's your bag. That said, I would still recommend Rainbow Valley to Gadsden
, as it's a great representation of the park. Let's be honest, though, you're better off just going to the White Tanks.