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No you've forgotten smooth's point, because the 51% attack requires ongoing hashrate expended by the attacker indefinitely. The network eventually heals when the attacker stops.
The 100X attack is death star. The chain doesn't heal (even after the attacker has stopped mining) without external intervention of a fork, because the difficulty is in the stratosphere so thus no block is ever created again (or not for a long, long time such as years).
I must admit I am most frustrated with iCEBREAKER, because he is intellectually dishonest (probably because of ignorance but I am not sure). You can fiddle with the difficulty algorithm to try to auto correct from the 100X attack, but you open other security flaw holes by doing so.
Agreed you and I, can agree to disagree.
So does the 100x attack since the attacker has to maintain the attack for a period longer than the number to blocks used by the difficulty algorithm to calculate the change in difficulty. So my point is why would the attacker not just fork the coin and set the difficulty to some insane high value?
Edit: I am still waiting for the answer to: For how many blocks do you want to maintain the 100x attack for?