He has a great typing and Ability: Snow Cloak to make a great Hail sweeper. He has AMAZING Attack and HP, and a great movepool. As for Rhyperior, he fits a different role as a Sandstorm sweeper. He does have a double weakness to Water and Grass, but he makes a good partner with a Pokemon with Storm Drain in a double battle. Why? LightningRod absorbs the electric attacks directed at the Water type, and Storm Drain absorbs the Water moves. As for the Grass weakness, well, you'll have to get around that. So yes, both of them are good, but they just fit different weather roles.