It's roughly a subway stop east of it - the hotel I stay at when I visit is almost at the exact point on that map - but remember that Chinese maps and GPS do not line up (check that spot on google maps and then turn on the photo layer you'll see that the streets don't line up) - the actual spot looks like the mall even further east.
Huaqiangbei is legit (and a wonder!) - the spot that would be a real smoking gun is the Huaken Building (aka the "Dodgy Cellphone Market") which is south of Shennan Middle Rd and between the spot on the map and Huaqiangbei. That place is pretty amazing in its own right, at the east end people sell bits of phones, dead phones, 'recycled' phones - they are torn down into parts which are reassembled onto new PCBs and resold at the west end of the building - it's full of lots of little cubes, people each doing a part of the process and onselling their work product to the next person - if you ever thought your phone can't be worked on by hand, can't be fixed, you are so wrong, these are real professionals - they take junk and make it real again.
If the phones were simply being recycled it would be wonderfully OK, even if Apple hates the idea of this sort of grey market, they'd rather we threw them away so they can sell new ones. As I understand it many of the Apple chips these days are 'paired' at the factory, you can't just replace one (and they have to pass through the above process together as a unit) this may mean (I'm completely guessing here) that they're still screwed if the user wont erase their phone, even if they completely remake it