Groucho:My two cents, go with PDL as they have a long history of quality in NZ. We had an electrician install some extra points to which he said he'd discounted the sockets for me as he doesn't make much on them which ended up being ~$22 each. Although I don't remember their brand they were supposedly Australian made but pretty cheap in their tactile function and aesthetics. Two years later the spring gave out in one switch that is used most days and was a bit spongy. I rolled into a local electrical wholesaler as a cash buyer and bought a replacement PDL unit and paid $2 less than the original cheap sockets.
$22? An HPM double socket from Bunnings is $18.49 inc. GST. Some discount! And if you managed to buy a PDL socket for less then my point about "your sparky" making a mint still holds. That's not to mention the voodoo pricing structure that most wholesalers have: first, the retail price is comically high, but no-one pays that; second, the price you pay depends on who you are, who you work for, and how the staff is feeling that day; third, the price will change depending on what else you're buying. And so on. So you can never compare like for like and you can never know if "your sparky" has offered you a genuine discount or is having you on.
Plus, it's all made in China for pennies these days. Where's the value?