i personally prefer the 001's in all the aspects u've mentioned, especially with soundstage and comfort. the soundstage issue is simple to address: stax is very open, ety is extremely closed (tho ety research does achieve a very impressively "wide" soundstage for such isolating and deeply inserted canal phones). as for comfort, i'm guessing that the staxes were far more comfortable for me simply because they were made for smaller ears (stax is japanese (small ppl), etymotic research is american (big ppl), i happen to be chinese (medium-small ppl)), but i don't think i've ever heard complaints about the staxes not fitting well on anybody, whereas i've heard more than a couple of ppl talk about how their ety's don't fit. of course, for every 1 person that talks about their ety's fitting and every 1 person that talks back, there're prolly 15 other ppl whose ety's fit perfectly and just don't talk at all...
i do think tho, that u should base ur decision on whether or not u want isolation, simply because one of the phones is
extremely isolated and the other is
extremely open. consider what u'd be using these phones for... for example, if u travel a lot on a plane or on subways, u'd prolly want the ety's (hearing protection is very important...
). but if u just want to sit in a park, browse a new novel, and hear some birds chirping and children playing in the background of ur debussy or something, the staxes would be perfect...
my 2 cents, hope they helped!