It's might actually be more useful to run 5 Spe IV's on TR Altaria, so it can outrun and OHKO 0 Spe Scrafty outside of Trick Room, since Scrafty annoys quite a few setters with Knock Off and Fake Out. Yeah, the speed won't be helpful versus Fake Out, but the subsequent turn, you might find having it might be useful. Also, there's very few things worth having min base 80 for anyway, only regular Gallade and Chand, neither of which is doing anything to Altaria anyway.
Also
Qwertypops, Mega Altaria has an excellent defensive typing (7 resistances and 1 immunity), and can handle quite a few threats, including pretty much every other Dragon, and virtually any fighting type, amongst others. Altaria can run Earthquake, Tailwind, Heatwave / Fire Blast / Flamethrower, Safeguard, Dragon Dance, and even Ice Beam, and can attack from both offenses, none of which Sylveon can do, so don't say Sylveon does the same job. Altaria can break past bulkier Steel types, such as Heatran or Ferrothorn, which Sylveon can't, and Aegislash can't just switch in on it since it gets 2HKO'd by Fire Blast. Is Altaria as good as MKang, Mence, or Gross? No, no it's not. But it's definitely a threat, and is quite unique.