After seeing SuperReviews, I was curious enough to try the brown filter with the ER2XR to see if it brings out much improvements. I really couldn't tell much of the difference. There probably is some tonal differences, but no technical improvements at all.
Been listening to EVO for more comparison with the ER2XR, my other Ety I like decently enough (mainly for the bass). Actually, there is no comparison (except bass). The highs on the EVO pretty much stomps the ER2 in terms of details, separation, and imaging (I think this was the reason why I really dislike ER2SE with classic Ety bass, without that bass there's really nothing to be interested in). Imaging is pretty mediocre with the 2XR. Sounds just pop with the EVO, and the technicalities really shows. Jazz is a good test for this, and how much better the EVO images. Just another level on the EVO with Jazz. On the ER2XR I don't quite get much of the shimmery images of the cymbals, and the metallic instruments. It's really smoothed out that resolution is really lacking.
So, I don't really see the point of holding on to ER2XR with EVO around.
Also, I think I was wrong about the sound stage being about the same as the classics. The imaging just seems bigger on the EVO with the sound positioning being much more noticeable due to the much higher technicalities.