RE0 graph is out on Rin's blog. Treble seems just as peaky if not more than the GR07. Distortion however is extremely low. Channel matching is excellent. I was on the fence about RE0's treble, and the dips start a bit lower than I predicted. I wonder if this is typical of the RE0 since most people seem to rave about the linear and extended highs, which I'm not hearing or seeing in Rin's graph either.
That 7khz peak on the gr07 has significantly greater amplitude so the sibilance range should be more pronounced.