Here's where you are misguided: it's possible the 400i is "better" in some ways, this is not a judgement of them....but do they have better bass and soundstage? Nope. So are they better for movies? Nope.
Now throw in the factors of durability:X2 is more durable. Then throw in the factor of drivability: the X2 is more drivable.
I don't know how much more clearly I can explain it below: $200 the Fidelio x2hr is the best headphones for movies bar none .....fight me..... throw me out a better headphone I dare you!
Also, check this thread, see if anyone agrees with me
https://www.head-fi.org/threads/philips-fidelio-x2.723025/