I reckon OP did an excellent job actually, because all cans described - especially the ad900 - are very different to others...
Well, the ES10 vs HD25 isn't, but putting a CAL! together with something reported to be neutral and another reported to be bass light and to compare them, OP must've put in a lot of hard effort :)
Thanks :-) But really I just compared all the headphones I currently own, most of which I bought in the last few months, and they were a big variety -- I guess because I've been trying out a variety of headphones. To my ear, the CAL! and the HD25 are actually quite similar -- the HD25 just has a tighter, punchier bass and a bit more detail. The ES10 is very different from both of these due to its V-shaped frequency response and substantially higher detail level. Of course, the AD900 is much different from any of the others reviewed.
I recently got the V Moda M 80 in the mail. Once it's burned in more thoroughly and I've listened to it more, I'll add it to the review. Initial impressions are very good. Not as much detail as ES10 but much richer mids.
I have to disagree with your claim that the AD900 bass is correct in tonality, at least to my ears. Please try listening to the first 30 seconds or so of the track Fidelity by Regina Spektor on the AD900 and then on another headphone with strong bass. (I see you have the Denon D2000. I haven't tried them, but they would probably work for this purpose.) On the AD900, I only hear a one note bass on this song, and it doesn't even sound like bass -- if I hadn't listened to the song on other headphones, I wouldn't realize it has a bass line, but would rather think the bass line was a midrange note. On the ES10 or the M80, there are clearly multiple different notes of bass. Of course, it's possible that your hearing is different from mine to the extent that you hear multiple bass notes on this song on the AD900. I'm curious to know whether that's the case.
Well, I occasionally enjoy them. When I first got them, I was really impressed by the soundstage and detail level in the treble. After more listening, I agree that they are thin and the treble is too much. But when I'm in the right mood for them, they sound good for some songs. I'd say the FA-003 are like dark chocolate and the AD900 are like milk chocolate. Usually I prefer dark chocolate, but sometimes I like milk chocolate for the sake of variety. Still, I would consider selling the AD900 eventually, especially if I find another headphone that has an equally great or better soundstage unamped but better bass.