The difference between the Annihilator and the other tanks mentioned here (Dracula, Helsing, Smasher) is that those tanks were released in smaller numbers. The Annihilator cost about half the price of the Smasher when it was first sold. The biggest impact I’ve seen is the number of Annihilator platoons and what it does to matchmaking. I had a battle the other day where Green had a platoon of Annihilators and Red’s platoon was a couple of 40%ers in medium tanks. Greens absolutely steamrolled the Reds.
I’ve started playing my 252u or IS-6 if I get tired of the Annihilators.