(For the Kiwis) Here is VF's response.
I think you need to look at the quality of the chinese dual SIM handsets,
The latest VFNZ SIMs have gone back to 128k as the localzone service is now decomissioned and this was embeded in the STK on the SIM,
The only say Vodafone has on the SIM cards is the look / colour and what is in the STK (SIM tool kit) SIM cards are made to standards
I am not sure whether he is saying theirs are now the same design as the 2 Deg ones. If so I may swap it with them again but I happy enough as it is because the phone hasn't missed a beat since I swapped the SIM's over.