to each their own
the rs1i for me had better resolution and detail than the 325 - and noticably better than the 225 - it's a matter of preference but i prefer it to the HD800, and tesla beyers, which list for considerably more
the ATH i've never cared for - even the woodies
i think there's a couple of things going on here
in general, the last 10% is much more expensive than the first 90%, whether grado, senn (hd 600 vs. 800), beyer (880 vs tesla), or ATH (900 vs. woodies)
that's also true for source and amp
the other thing is that the last 10% is not really noticable unless you're running a system in balance (eg a killer source compared to a low/mid fi source when using low/mid fi cans and amp will will be even less obvious than the typical diminishing returns)
running an rs1i with an ECSS and pico it's not massively different than the 325, stepping up a meier opera, it's more obvious, moving to a benchmark and modded bottlehead SEX, it's much more obvious - from a portable (even a cowon), it's very subtle at best
same thing with the Senn 650 & 800, Beyer 880 vs. Tesla, etc.
same thing with and amp and source - running a grado 225 and meier stepdance an hrt II+ isn't so different than the hrt pro, etc. - using the rs1i or hd 800 and a bottle head or GS-1, it's more obvious
all that said, the rs1i is a particular flavor, much more so than the 800 or tesla - on par with the 701 but in the opposite direction
and it's also a matter of priority - few hundred more bucks for the last 10% of a headphone, not worth it to some - same thing for computer performance, photography, motor-sports for others
and finally, not just opinions, but literally how individuals hear (not just sensitivity but via ear shape) is different
so if your system, priorities and hearing have you happy with a rig - by all means stay there and count yourself lucky
if you're reading others' opinions and considering how they apply for yourself, consider the above