It’s a multi-role vehicle.
If we compare it to 11.7 SPAAs, the ADATS has an autocannon, which the ITO, TOR, and FlaRak doesn’t get. If we compare the missiles alone, the ADATS’ missiles are more maneuverable than the TOR or Pantsir’s at close ranges. The ADATS doesn’t suffer from the two-missile reloading system the FlaRak has, and its autocannon can hit up-close jets pretty easily. The Pantsir and ITO would honestly have to be the best SPAAs at the moment, but the ADATS 's 900mm pen ATGMs are enough to penetrate weak spots of enemy MBTs, with a maximum velocity of 1,027 m/s, while the BMP-2M’s ATGMs can only go 320m/s (with the proximity HE missile 9M133FM-3).
If you compare it to a IFV, like the BMP-2M, the ADATS can fire more missiles quicker than the BMP-2M, its autocannon is worse, but doesn’t really matter too much since it still works very well against the side-armour of Leopards. It doesn’t get a stabilizer, which is quite frustrating, but the suspension and smooth terrain (that most city maps have), makes it quite stable anyway.
Overall, it’s a very good vehicle that does not require a BR change. If anything, the new MBTs (such as the Leopard 2A7) should go up in BR to 12.0, to balance the matchmaking.
Which is entirely irrelevant due both how ATGMs are aimed in general, the inability of the ADATS to depress its launchers and its inability to fire said ATGMs while moving. The ADATS’s anti-tank capability is purely defensive and without a reserve load of ammunition generally leaves you completely out of ammo having to move to the point to resupply.
I don’t because it has worse missiles, it can’t fire its ATGMs while moving, it has a worse autocannon, it has no stabilizer, and it has a much larger target profile.
So part of the reason it’s 11.7 is because performance wise the people who play it do very well in it. This is for a couple of reasons.
One. It’s in the SPAAG line. A lot of new players tend not to research SPAAG, because quite frankly, US middle tier SPAAG especially are a struggle bus. Genuinely the worst. So the few people that do continue to research the line generally speaking are of higher skill level, which makes its stats better.
Two. It suffers the case of the CL. Mk 13 a bit. People played it up on introductiom back when it was insane and there were no GBUs or anything, and did very well. It was also classes as an SPAAG then, so people would first spawn it to kill tanks, which added to it’s excellent performance at the time. Also why it was classified as a TD eventually.
Three. It uses IRST to lock on, as well as it’s missiles having a smokeless motor/near smokeless motor. Unless you happen to be looking at the ADATS when it fires, you won’t see the missile coming, making it very effective at SPAAG.
I mean, and generally speaking, it’s a good vehicle. I am by no means a great top tier player, however if you look at my stats in the ADATS you could be convinced I’m pretty decent. It’s one of a few vehicles that I have above a 1.0 KDR in at that BR range, so.
Do I like it at 11.7? No. I want it at 11.0 with my M1 IP and M1A1. But eh, I can see why it’s 11.7 a bit.
As I mentioned in the above post, this was because people would first spawn it and then use it to kill tanks. This was back before a majority of ERA was around, so the vehicle did very well in the AT role. Gaijin changed it to TD for balance reasons.