So far I tried Lucky baby and Ergo, lucky baby when son was younger. Bought Ergo last month, I prefer Ergo, son is not that heavy (he is 16mths n weigh 12kg) when I use the carrier compare to carry him w/o the carrier.
I search online and happen to find a supplier which they do free delivery to your house and teach/guide you how to use. I bought organic material at $189. Saw it at shopping mall, it was selling more than $200.