1: Altaria breaks it into "90 damage or more" easy.
LOL ALTARIA
Easy prizes, anyone?
Sigilyph is objectively better than Latias EX for a multitude of reasons.
~It only gives up 1 prize on defeat, plus its HP-to-prize ratio is higher anyway - 90 to 80.
~Its damage output is higher (especially with Weakness factored in), and is compatible with DCE.
~It blocks more opponents than Latias EX does (the only thing notable that Latias blocks that Sigilyph doesn't is Bouffalant, and even then, most EXs do not have abilities anyway and can hit Latias easily but can't touch Sigilyph), thus allowing it to counter a multitude of threats.
~It has a Weakness to Psychic, which although more common than Dragon is not found as often on non-EX cards, and basically every Dragon save Hydreigon can hit Latias anyway.
3: it works in darkrai/hydreigon as an amazing tech.
Giratina EX is better because Shred applies Weakness
and deals more damage, for the same amount of Energy.
Latias walls more than sigilyph. It also 3HKO anytihng no matter what.
Nope, incorrect. Sigilyph walls more than Latias.
Are you people seriously trying to argue that Latias EX is better than Sigilyph? No. You're crazy. There are not nearly enough attackers with Abilities to justify that statement, and on top of Latias' objectively terrible damage output for an EX, she cannot do nearly as much (granted, Sigilyph does about as much, but blocks a lot more and only gives up 1 prize).
The only thing that Latias EX handles better than Sigilyph is Darkrai EX, and even then Darkrai decks have ways to deal with quirky threats, especially with the advent of Quad-Sigilyph.
Please, go home.