I have the Explorer, and i love it. Espcially the 2 configurable side buttons. I dont like the IO, as it is too small for my hands, and the placement of the sidebuttons is so that i can never use the outside side button, whereas i can use both sidebuttons simply with my thumb on the Explorer.
But in the end its just personal thing, depending on how big or small your hands are and how it 'feels' in your hand. Like said above, go try em out at a store.
-AB-