Hifiman HE300? They're very warm and quite frankly, muffled sounding, especially compared to clearer phone like 840. IMO HD600 is significantly better for that kind of sound signature.
Though I heard there's a mod for HE300 if you're comfortable with opening up your cans.
Haven't heard T90 but I've heard DT trio and T1, they're all very impressive in regard to soundstage, imaging and detail retrieval, probably among the best dynamic for those.
MA900 is like a grainier HD650 with even bigger soundstage.
Yes that is the problem with HiFiMAN , revision consistency ...the one I have is having tremendous extension and although they have rolled off bass (REV-3) they are still warm
The detail and clarity that they have is unlike anything I've heard , I own the 650s (Not the 600s , which I know don't have the relaxed treble that the 650s have) and yes they might be a better phone in general but in terms of Female Vocals the HE-300s hands down are better , wonderfully extended and bodied
Used to have the ma900s too but the grain was bad , typical Japanese headphone sound
Also the sense of air is fantastic due to the extension from the upper mids to the upper treble