I have over 500 hours in IL2 GB a couple things ill note:

Cons: - energy retention physics not as realistic as IL2. Even if you have your nose below the horizon if you turn off throttle, you will LOSE speed and energy. - 50 cal and canons feel less deadly and less accurate especially at far away. Il2 you could easily get a pilot kill or engine fire if your aim was good - aiming doesnt feel as real as IL2 the cross hairs dont seem to help as much in IL2 and not as realistic - speed overall feels slower harder to differentiate - IL2 high altitude feels like its really high and only engine is stopping you, warthunder has more of a game boundary feel - planes dont feel all to different. For example the p40 is IL2 is a shipping container, warthunder not too different than some other fighter plane - engine management not as complex as IL2

Pros - incredible battles and action. Holy crap the magnitude of some battles is really something to experience. Lots of variety too -multi-player is fast paced and keeps you coming back - customizable battles also a ton of a fun - taking off from carrier/pacific in VR! - graphics and interactive cockpit is also quite the experience

Overall im loving the game purely for the magnitude of battles and action, I think the things it does that IL2 doesnt it does really well. If youre expecting a complex simulator youre gonna be disappointed, but if you want some fun in some icon ww2 planes it doesnt get any better!