We had a good discussion about this some time back
These are software implementations of headphone amplifier circuits. If you want to truly understand what they are doing, and their differences, you need to go research the circuit that they are emulating.
As far as “what is better” it’s whatever one sounds better to you. There is no right answer as everyone hears soundstage in headphones, and even from headphone to headphone, a little differently and that’s why multiple filters exist. Just listen and decide.