Ooh.. the R-50 does look promising, and thanks to you, piqued my interest.
I've also reviewed the GR01s, and mostly listened to them against the GR07. From reading my review, would you also think that how I'm describing GR01 is also similar to how you would describe the R-50? I'm quite curious.
Almost to the T, the only thing that might be a little different is the way I hear the soundstage. I feel that the R-50 has quite a large sound with the width about equal to the GR07's but the R-50 has better depth imo. Like you with the GR01 I think the R-50 has a little bit better separation over the GR07. I really think the GR01 and R-50 must sound almost same.