Originally Posted by Fat Nyktos
And, well, I agree. Specs Latios HP Fire really sucks for every spread, but it sucks a little less for the fast ones. The thing is, "a little less" really means "a little" here. It would be one thing if high speed spreads could actually beat Latios when it used HP Fire. In that case, I would likely agree that high speed is better. However, all it does is make mispredictions a little less costly. You can get a spin off or deal some damage to Latios before being KO'd. But you are still KO'd unless Latios has taken a bunch of prior damage. Really, against Specs Lations with HP Fire, you're probably better off switching in Heatran than CAP 5, regardless of stats. So while it's a regrettable situation all around, I don't think it justifies high speed.
It's worth noting that CAP5s highly or fully invested in HP/SpD+ with ST ratings around the 235/240 mark running Sitrus Berries (or Enigma/Occa berries, I guess) are even covered against sun-boosted HP Fires - which won't 2HKO out of Sun and will trigger the Sitrus in it. As a bonus, depending on the specific ST rating CAP5 might actually have the liberty to drop a couple of SpD EVs to ensure that HP Fire brings it into Sitrus range, freeing them up for Attack or Speed.
Faster CAP5s with STs around the 200 mark can avoid the HP Fire 2HKO with Sitrus berries too - but this necessitates quite a bit of investment in both HP and SpD, which completely defeats the purpose of the extra speed in the first place. Occa sets would do the trick, but it's hard to imagine them being widely used.
In that sense, high Special bulk makes CAP5 a more complete Lati@s check than high Speed - whereas fast CAP5s fully invested in speed can be overcome by a Latios running the right (commonly used and competitively viable) move in the Sun, those that tend towards outright walling can potentially stop it in its tracks, sponging its entire movepool bar gimmicks like HP Bug. So I think brute tankiness trumps speed as far as countering Latios is concerned.