I recently had the chance to try a friend’s BOSE AE2 on some tracks I know very well so I will give a little feedback.
The AE2 is a portable circum oral headphone. So your ears are inside the pads instead of outside like with the HD25 of sennheiser for example.
It a small circum oral and my ears where touching the pads due to the little size of the cups. Also the pads are made from synthetic material that are not the best if you compare to sennheiser or beyerdynamic or akg or audio technica or whatever other hifi brand velour pads.
Lets go to the point: The sound is very good, goes deep in the bass. no really subs like on the Superlux HD330 for example but consistent compared to a HD25. I liked the sound and tone in the high frequencies, very clear and precise with good stereo an panoramic placement. lets say very good on this last point.
The efficiency is good and my galaxy note was driving this one very well. Good balace between the channel etc.
Construction wise it feel cheaper than a HD25. The cable for exemple is very tin or the plastic used are not in the same league.
OveralI I think its a good choice in front of a HD25. The confort is superior and it maybe more suitable for someone who have only one headphone and wants an all rounder.
For the others (like me) “the initiated” crew with full size headphone at home the confort for short transportation is less a criteria and the choice between this one and a HD25/amperior maybe difficult. A question of taste but its really a very good and easy to drive portable headphone.