Just looking at some raw stats (with full provisions):
DPM: 2709
Penetration: 170
Aim time (WoTB Compare is still off but good enough to make my point): 1.68 sec
Speed (F/R, kph): 35/15
HP:1500
Hull/Turret Traverse (deg/sec): 29.2/39.63
Turret/Hull Armor: 208/120
Now lets look at a mediocre T8 Heavy
VK 45.02 A
DPM: 2270
Penetration: 215
Aim time: 1.87 sec
Speed (F/R, kph): 38/16
HP: 1750
Hull/Turret Traverse (deg/sec): 49.3/29.16
Turret/Hull Armor: 192/125
Now a really a good T8 Heavy
Emil I
DPM: 2075
Penetration: 217
Aim time: 1.99 sec
Speed (F/R, kph): 35/20
HP: 1750
Hull/Turret Traverse (deg/sec): 30.17/24.82
Turret/Hull Armor: 187/130
I know there is a lot more than just these hard stats (like armor angles, weak spots...etc). My point is that throw on an extra 200 HP, 30 more pen, and change nothing else and the Annihilator is a competitive if still not slightly OP T8 heavy. This thing has the second best DPM of all the T7 heavies, insane aim time for something that does 630 damage, average speed for a heavy (key phrase here being "average", not the slowest), a basically impenetrable turret and upper plate, and a turret traverse speed that can fend off FREAKING lights.
Even though the Smasher is known to be game breaking, I've only found it to be an occasional annoyance because it's rather rare. The problem comes when there are 2 Annihilators on EACH team basically 1 out of 5 games. When I see more Annihilators on the other team, I almost just give up (though my hatred for Annihilators still drive me enough that I take every chance to destroy them). Especially if they are platooned and work together, they can take out a freaking T7 heavy with a slightly-better-than-average burst from each. The worst is when the red team has two platooned Annihilators and you have none, which happens more than it should.
Even when I'm in a T8 tank (especially in mediums), I treat them like T8s because their insane turret traverse. If you are in anything slower than a LTTB, that turret will catch up to you eventually. I'm not even that careful with a Smasher because I know that they have a such a slow Turret traverse and circling them is not a huge issue.
I propose two solutions:
1. Nerf the turret traverse, the aim time, and maybe the accuracy. Nothing dramatic, but for something that does 630 average damage, the accuracy shouldn't allow it to land all three shells at 100m and keep up with lights circling them. Maybe something like 30 deg/sec and 2 sec aim time (the Tiger 1 has 2.36 sec aim time for crying out loud).
2. WG cared so much about balance that they brought missiles into the game. (BTW I don't believe missiles were that OP. Sure, they had their moments but nothing game breaking especially after all their nerfs, but that's another topic for another time.) Then they said "Ok lets only allow missiles for special events". THERE'S THE ANSWER TOO ALL THE PROBLEMS. Only allow the Annihilators for special events, problem solved.
I really like this game, its one of the only few games that I've actually enjoyed playing that's why I am complaining. When something makes you despair even before the game starts, you know there's something wrong. I don't have the time and money to buy every single take and complete every mission so it takes me some time to grind up the tech trees. Then I hit T6 (where I can be potentially one shotted), T7, and T8 where I have to face these behemoths every other game, it nearly breaks my will to play this game.
WG if you love your game and players who have spent money on your game as I have, PLEASE DO SOMETHING!