Mind u my gr07 mk2 has slight(maybe 5 pc) volume loss in my lelt ear and I will send it back tomorrow for warranty.
soundstage-b3>>>>gr07
u won't believe how big the diff feels ,damn like moving to an opera house.
bass-quantity almost same but havi is more loose compared to gr07 and nothing beats gr07 in drums.period.
but this diff is minor one,havi has pretty solid bass,certainly for all genres
mids-gr07 >b3 due to smaller soundstage feels cleaner with black background.havi is laid back due to giant soundstage
highs-sore spot for havi,extremely sweet,lacks punch and extension could be better,most noticeable aspect vs gr07
OTHER
timbre-gr07 has a distinct one,anyone having them knows what I mean
vocals overall-laid back in b3 again due to soundstage,some may not like it before proper brain in.i was one of those,lol.
clarity-b3 is extremely clear ,flat sounding iem.also lack of treble energy may make the vocals even more soft making it appear even more clear.
overall--its very very diff from gr07 and imho instead of going for others in 100$ range u should het this to feel what other side with massive soundstage feels like and trust me it beats gr07 for certain recordings especially classical ones.
The only weak spot that I can point out after a day of listening is treble which is even weaker than m3,forget about gr07.
Other being the build quality.
I will listen more and post more impressions later on especially vs m3.