Question about stax

I haven't compared them myself, but I'm reading that the new 307 / 407 headphones have different drivers than the old 303 / 404 series, and the way the drivers are fixed against the baffle has been improved as well (they are not stick now, but rather encased in a resin case). I've read only one report on the 307 and the guy said it sounds etched, much like the old 303/404, while the 407 was much better (which I find surprising, as the difference between 307 and 407 is, as with the old models, only the lower capacitance cable on the better model). Everybody seems to like the 507, while the 407 was considered to be pretty close. The sound is said to be warmer, more detailed, with stronger and tighter bass than the old series, and without etch (in the 407 and 507 case). In other words, a clear improvement.

The 323 amp is said to be better that the 313 it replaced, mainly because of the better power supply iirc, and has greater voltage swing (which is a good thing). Some people disliked the 313, but I've read only praise about the 323.

Should I buy a new Stax combo now (and provided I didn't have the money for an O2 system), I'd look into the 307 or 407 paired with the 323, or perhaps the significantly cheaper 2170 (207 + semi-portable amp), but the later only after auditioning to make sure it's not much worse overall than my current 3030.

The 3010 consists of the 202 headphones (lower than the 303 / 404, but some preferred them for better tonality / lack of etch, despite being somewhat less detailed and extended than the higher models) and the 310 amp (worse than the 313). I'd rather put my money on the 2170, or perhaps the previous 2050 or even the older 2020 combo (used in the last case).

Please take into account that all this is based on reading around here, personally I've only heard my own Stax system, the 3030.

Hope it helps.