Hi guys, this is my first post here.
I have a/b'ed the EX600, EX1000 and the GR07 on multiple occasions using Sony hybrid tips. I believe that the GR07 clearly pulls ahead of the EX600 in terms of smoothness, bass presence, and overall tonal balance. I felt there was a certain grainy quality to the midrange of the EX600, or what others would describe as dryness. Overall, I consider the GR07 a much safer choice as its sound signature is generally more versatile than the EX600.
On the other hand, the EX1000 and the GR07 sound more similar to one another than to the EX600. The EX1000s have the GR07 beat in terms of dynamics, which I feel is a major weakness for the GR07, making it sound flat in comparison to the Sony flagship. As a result the EX1000s are more effortless in their presentation and less fatiguing. However I can't make any deeper comparisons without owning the EX1000s (the EX600 comparison was fairly straight forward however).
All that being said, I feel that right now GR07 is the mid-range value king. The EX1000 is great but at its price point there is a lot more competition.