Given the post 1 July 2013 tightening of L visa requirements (if obtained correctly), I see Shenzhen/Zhuhai VOAs as massive backdoors.
I used to get L visas for family members (and on one occassion for myself when my HRP was nicked) by paying a sizeable chunk of money to China Travel Services (the state-owned travel agency in HK) for a 0.5 day turnaround.
When my mum wanted to take the grandchildren golfing in the Mainland I had to set up Mum's courier to run to my SIL's place, pick up the childrens' passports and photo (the photo is the only work my SIL had to do), hand them in with the forms I precompleted for them and run the passports with the L visas back to SIL. We don't take chances with the VOA.
No longer valid after 1 July 2013...instead, my SIL is meant to hoff from the suburbs into Sydney City for the visa centre and apply from there, and pick up her childrens' passports from there. Fat chance she'll do it in advance, even if my mother specifically asks her to do it.
But in my mind this procedure is still more compliant than the new "standard" policy and the backdoors the Mainland authorities have maintained (Shenzhen/Zhuhai VOAs) or the elephant in the room that they have opened up (72h VOA which we have all gamed to bits...)
Increasingly I really don't get Mainland policy-making...
And in today's news, India has changed from being the biggest PITA visa to get to being moderately easy with e-visas for Australian, US and 41 other countries' passport holders. Too bad HKSAR not included, not that the missus is very keen to visit India anyway.