I dumped my 007MkI and KGSS after 4 years of ownership in favour of the LCD-2 Rev1 and B22 back in the day. Given I like the Rev2 better than Rev1 and LCD-3 RMA better than Rev2... I don't see the 007 MkI being competitive. Back then the greatest difference given similar tonal balance was the lack of grain and great drive of the LCD-2. It wasn't massive but the orthos, even the HE-5LE, were cleaner and less passive.
That the 007MkI barely fit and put massive pressure on the top of my head didn't help its chances. Which is why I know wonder about the 507 and 009 which should fit.