To me the GR07 do have better isolation with the large hybird tips. I find the sound of the GRO7 more bolder then the MH1. On my Sony X1060 the clear bass was most of the time at 0 and at times 1+ with the GR07. But with the MH1 I have to boost the clear bass as I find it too thin sounding and lacking bass at flat.
Hmm, you must definitely have bad seal with MH1C then. Because Vsonic GR07 have no way more bass than the MH1C. Yeah, the have more detailed, controlled and quick bass, but the ammount and "punchness" is not so high. When I was listening to GR07s at home, I felt everything was ok, bass included. But when I tried them outside on the go, the bass almost disappeared owing the averagne isolation.