So you're saying Extremespeed is the sole reason Rayquaza is Uber? I actually said to ignore Extremespeed for the sake of the comparison, as I figured most people would say Rayquaza is still Uber without it. About the bigger movepool, what I was arguing is that in reality it doesn't actually make that much of a difference. Rayquaza is unwallable, Salamence is unwallable. Who cares about Thunderbolt when Salamence 2HKOs every single bulky water with Specs Draco Meteor or +1 Outrage. Overheat and Surf are non-factors when you have Fire Blast and Hydro Pump both doing the exact same things. My point is that in order to beat both Salamence and Rayquaza, your only option is really revenge killing. I understand that Rayquaza is more threatening offensively with it's higher stats, but when Salamence is KOing all the same things, and with no Lugia to take on the DD set, it comes out to the same thing.
And this is all assuming an Extremespeed-less Rayquaza, to make the comparison more accurate. I think most people would agree Rayquaza is still Uber without Extremespeed.
Yes, Rayquaza is Uber without ExtremeSpeed, but it certainly doesn't hurt. Here are Rayquaza's advantages over Salamence
1) 15 more points base attack. Doesn't sound like much, but Max Jolly Rayquaza has only 6 points less attack than Max Adamant Mence. And considering most 'Mences run a +Speed nature and actually reduce attack a bit to bump up SpA (and Rayquaza can afford to go Adamant due to ExtremeSpeed), Rayquaza comes out quite a bit ahead here. Max+ Attack Rayquaza has 74 more attack than your average DDMence, which is equivilent to a 20% increase.
2) 40 more points base Special Attack. This is really significant. Rayquaza hits a max SpA of 438, which is a full 88 points above Max SpA Salamence. With Specs slapped on, he has a 132 point lead over Mence, which is certainly signficant. Also, Negative Nature, Minimum Special Attack Rayquaza still hits 302 SpA, while Salamence hits only 262 SpA on the standard Dragon Dance set. So Rayquaza gets max Attack, an extra 4 points in HP, and a nature that's defensively neutral while still maintaining significantly higher attack scores from both ends of the spectrum.
3) Defenses. +10 HP, +10 Defense, +10 Special Defense gives Rayquaza defenses that are more on par with Garchomp's, allowing him to take switch-in hits, special hits, and revenge kill hits that much better. Add this to a Sandstorm immunity granted by his ability and his lifespan suddenly goes way up.
4) Movepool. Rayquaza gets Swords Dance in addition to Dragon Dance, which is a major boost for a stat-up set. Combine this with ExtremeSpeed and you have a hellishly powerful nightmare of a Pokemon. Anything faster is going to have to contend with a +2 LO ExtremeSpeed, and anything slower is likely going to eat an Outrage, Earthquake, or other powerful move. It's like getting the benefits of DD's speed while still getting a much higher attack boost, which, let us remember, was one of the main factors in Garchomp's banning. Also potentially notable are: Bulk Up, Overheat, Surf, Thunder/Thunderbolt, Energy Ball, Waterfall, and every single worthwhile move that Salamence gets.