Went with my family to HongKong in September and my dad decided to use a Matrix Sim Card to save on international roaming charges. They were quick in delivering our pre activated sim card. it worked good in terms of call connectivity. Network coverage was also good. And last but not least, their billing was appropriate and was according to my call usage, unlike what I have read in a few places. All in all the preference of using Matrix Sim Cards really helped us!