I read your review the other day, nib. didnt know that as you. I thought it was pretty interesting mainly because when the Westone 3s came out, people on Head-fi were praising them up and down and saying they would demolish anything shure was putting out. Like they were several steps above anything else available.
a few years (and one more driver) later, and it looks like its not a one way comparison anymore. Either Shure improved the 535s or Westone messed up the 4s (or a little of both)
on another topic, in my recent quest to upgrade all my audio shit one last damn time, I ended up getting a Burson HA-160 amp. great price slightly used on CanuckAudioMart (500 instead of 700) so I jumped on it and - MOTHER OF GOD - it is so good.
Having moved from an E9 to a Schiit Asgard amp and seeing little difference in my Grado RS2s, I thought I might have hit the limit for what the RS2s could produce. yknow, they might get a little better here or there with various amps but nothing major.
But the Burson really makes a noticeable improvement with these little guys. I didnt expect the difference to be so noticeable without any extensive testing but I was able to tell a difference in the first few songs I picked. (I got the Burson in anticipation for a future pair of cans, not really for the Grados, btw)
The main improvement is the ability to render fine detail on very loud and troublesome passages. main example that comes to mind is from the Tron: Legacy soundtrack. there are a few tracks near the beginning (Arena, Rinzler, etc) where there are lots of very loud drums layered on top of each other. up till now, this section would always sound a little compressed and distorted on any headphone I used. not anymore. I had thought it was a limit of my headphones but it was really the source/ amp that was holding that back. now the details of the drums and the various layered sounds feel much more solid and easier to discern.
Im also noticing a few more slight details in other songs sound a bit more prominent. things like shakers and tiny high pitched percussion hits are more clear and very low bass now has more distinct notes. all of those now sound a bit better than before, adding more texture to the sound.
great, great stuff.