There is no way you are serious here, tell me what legitimate Pokemon can take a DD Outrage or 2 Outrages and OHKO back (that is what a "hard counter" is). Cresselia, P2, very bulky Suicune/Vaporeon ... that is all really. Even it's checks can only come in safely on revenge kills (Mamoswine/Weavile) as they run the risk of being Outraged/Fire Blasted.
For the bulky water counters, they often support an entire team, can you imagine Mence taking them down to 20% or whatever and then DDGyara or Infernape just sweeping?
Alright look at it this way. If we -know- Salamence is a of a DD variant, than it has A LOT of hard counters. I would switch in Swampert/Vaporeon/Suicnue all day long. What is it going to do? Blind Outrage on the switch? The most likely move it does is either of it's 2 other offensive moves, normally EQ/FB or DD. If it DDs, your water Poke is only taking 6% on the switch in after Leftovers. We're assuming same conditions here. Salamence had to take 25% just to get in.
Now what? You're gonig to Outrage me and die? You say that it opens up for Infernape/Gyarados. Well those two can do the same thing. What are Gyarados's hard counter? We'er going to ignore Cresselia/P2 because they "stop" both DDGyara and DDMence. Gyarados can weaken all of it's counter significantly as well. Bulky Rotom is still going to be weaken enough for an Agility Metagross sweep, Celebi/Grass Pokes can be beaten alone with Bounce, and Vaporeon absolutely needs HPElectric, or it could lose to either SubBounce, DDTaunt, or DDRestTalk. Because Salamence weakens one Pokemon for another to sweep doesn't make it uber, because EVERY Pokemon pretty much has that ability.
The only reason why you would possibly bring up DDMence being of any importance to whether or not it is uber relates to only one thing. Earlier I said "if you knew it was DD." That's it. That's the only reason why it should be brought up, because you don't know between the two. And let's face it, any other Salamence that isn't DD or Mix is a joke. Scarfmence is a joke, Specsmence is a joke, and bulkyMence is as well. You are overly concerned for two reasons, because if yuo switch in ScarfJira/Heatran on a DDMence, you might lose it. If you switch in Swampert on a MixMence, then that's gone. But seriously, DDMence has hard counters and is -not- a threat -If- (and a big If) you know it was DD.
On an unrelated note. Also DDJollyNite is absolutely fine. With all the raging Jolteons out there, I'd say it's a good investment to make. And with the power difference, if you're using Life Orb, you're probably not going to notice it, and if you're using Lum/Yache/Leftovers, then that 10% boost isn't going to help KO much either casue you're using it for more defensive purposes most likely.
On another unrelated note. A year ago people wanted to test Ho-Oh and Darkrai and now so eager to ban Salamence...smh.......................