Storm, most Lane #1 balls can cover most conditions, except for the extremes. In that case, you will need an extreme ball, like the XXXL or the Super Carbide Bomb.
The Pearl Uranium works better on the fresh, because of it's smooth roll, where the Dirty Bomb jerks more off the dry.
As Steven has stated, it all depends on your game. For the most part, all of Lane #1's medium range balls can be used to work well on almost any condition, depending on your game and/or ball layout. =:^D