I had used a matrix sim card in Singapore for about 10 days when I was there to get admissions in one of their universities. I was glad that we had decided to use their services cos it really helped. I could easily navigate through places and also it was totally stress free to just make a call to know about the office availablilty and all. Had I not carried the phone, which initially I was thnking of, I would have been running poles to make calls. With matrix sims, atleast all these things were taken care of.