Looking over the two, I have to wonder why everyone seems to pick Archon over Tirtouga. Archeops is a speedy glass cannon, yes, but its ability clips its wings super-freaking hard. Carracosta, on the other hand, has nice defenses (and even better special defense if you can pull off a Sandstorm), along with very nice attack-- and its weakness is obviously its low speed and double weakness to grass. Still, it has Sturdy to protect from getting OHKO'd, or Solid Rock to take the edge off those super-effective attacks. On top of that, it gets Shell Smash, which lowers Defense and Sp. Def one stage, but is the equivalent of Swords Dance, Nasty Plot, and Agility/Rock Polish all in one move (also the option of Curse if you don't want to take that risk). It's more versatile overall, and can easily work as a glass cannon or a slow, heavy tank. I want to raise one. :S