[_old_dude_]

APK is now more a delivery package format than a real executable format now.

On recent Android devices, the APK wil be recompiled to machine code on the device after a small number of runs (to gather code statistics).

So you are comparing an apple and a robot.

[lern_too_spel]

IPA is also a delivery package format. The big difference I am aware of is that IPA encrypts binaries, which will make them less compressible.