I'm a massive fan of war Thunder, been playing for over 3 years. While it is without doubt the better game here, I think its worth pointing out that War Thunder and World of Tanks are, IMHO, aimed at different audiences.
WoT is a lot bit easier to get into, full of options/choices etc, the actual gameplay is much easier to grasp. War Thunder's arcade mode is s similar experiance, but its Realistic Battles where I think WT rewards players with more tactical depth.
Its harder to get "good" in WT, but its a lot more rewarding because of this!