Wow, I prefer Excadrill, and by far. I don't especially like it, but I appreciate its double type. And, we needed another mole Pokémon.
Concerning Gigalith, it's just one of the many awful-looking Pokémon of the 5G, it and its pre-evolution. Seriously, a gemstone Pokémon, it was a good idea, but Gigalith only looks like a monster drawn by a kid (anyway I though of that when I saw it the first time). And, we have way better rock-type Pokémons... Even if Excadrill isn't especially strong, it's double-type is almost undivided.