Thanks in advance.
Edited by Invalid - 1/13/14 at 6:09am
Amperior are said to be slightly better than the standard HD25. I don't know much about the aluminium ones, they're probably similar to amperior just different impedance.
The momentum are completely different headphones which I believe have 2 different models - on ear and over ear.
I have the Amperior, Aluminium and Momentum (and had the HD25ii). I find the Momentum the most relaxing listen and probably suited to largest range of music genres. However, I enjoy the impact of the Amperior and Aluminium for more toe tapping fun. Regarding Aluminium VS Amperior, to me the Aluminium has more bass presence, maybe due to the pad difference. They are both easy enough to drive from a DAP, but the Amperior is especially easy from any source. I would suggest the Amperior if using a DAP only, then the Aluminium if using a DX50 / AK100 / headphone amplifier etc. Just my thoughts though.