I love my track IR, but the rear views out of my favorite planes are terrible (F4U & F6F). So I still have a hatview for looking back, up and forward.
Also.. the implementation of TIR in this game is really weird as well, since when i'm using only the track IR and i look backwards... say back and left, looking over my left shoulder.. If I move my head right to see around the seat, the game view moves LEFT as if the game is thinking my character head is still looking forwards. Which is opposite of what it should do.
I know this isnt my TIR setup, since it works as intended in DCS, BMS, war thunder and my racing games. AH3 just seems to interpret left and right X axis movement while your head is turned backwards without considering that twist. Same if you look pure left, the X axis movement is interpreted into forward and back now (since you're facing 9-oclock). without taking twist into play.