Just came back from HKG, and I got 2 cards from Ap Liu Street - Shamshuipo.
1. CSL card - it's a 'Disney car' edition and I paid $50 for a $88 card - used unlimited data (7 days - 168 hours - it automatically cut off after that) - a newer edition cost $60;
2. A FM (2G) card - $30 for 2000 minutes, so far so good.
I didn't buy the PCCW one because I bought a full price one at 7-11 a couple of years ago (used on a stupid phone) and it lasted very little. Also when I was at the stand there was a guy saying he didn't want PCCW either.
You can get a PCCW one for as little as $20. There are lots of stands selling cards, not just on Ap Liu Street but on the side streets too.
If you do buy it, ask the shop owner to test the card for you before you pay. They have a special test phone that they just need to slot the whole card in and you can see the value.
I put in both my cards into the phones and checked before leaving the shop.