@kwisdumb: I agree. Crobat is probably the most quirky of the bunch, and what you really have to do is use enough support to get that poison to bring them low enough to knock them out (or knock them out). Such cards include Weezing GE and Ariados MT (the former increases damage, the latter increases retreat).
Unown G is still legal in the format, however, it is not as often used anymore, since most of the current metagame decks do not revolve around attack effects. Warp Point, however, is used a lot.
It's probably the free retreat bit that hooked me. Kingdra Prime has potential that is much easier to bring about, but...Bright Look. Ow. And seeing as many (but not all) decks run Bright Look, it's a risky world for Kingdra. (Then again, Crobat's weak to Luxray too, so what am I whining about?)
I can't understand the Tyranitar love, though. 160 HP on a Stage 2 is high, yes, but his attacks are much to be desired. Power Claw is good because it bypasses Poke-Bodies like Donphan (so with a belt it will do 80), but Donphan can usually OHKO the guy right back, so it's a mixed blessing. Darkness Howl is good in a straight-out Dark deck, but if non-Dark techs are used it can severely cripple your own bench. (In fact, the only Dark tech I can think of is Darkrai LV.X, or Darkrai MD.) Megaton Tail is...ehh...debatable. Is the loss of three cards really worth a 4-for-140 attack?
If anything, Ursaring Prime can hit a lot higher than Tyranitar Prime for a lot less setup, in my opinion. Expert Belt will give him 130 HP (stage 1), and that plus Berserk grants him a +80 to all his attacks. Still, I'm a sucker for Steelix because his only real fear in the format is Blaziken FB. (Same reason why Kingdra is so good - that's the only real Fire-type threat around.)