Chef Pon and a partner started Chef Pon's Asian Kitchen a while ago, but then he parted ways with his partner who retained the Chef Pon's Asian Kitchen and Chef Pon (this is confusing, right?) opened Chef Pon's Sawaddee - in Rheede Street (map).
Although I've never eaten there, I've heard that CP Asian Kitchen isn't what it use to be. By contrast I've visited CP Sawaddee and found the food to be exceptional. We normally go there for their sushi (you HAVE to try the Chef's Special), but I've eaten two of their Thai beef meals and they we're both brilliant.
In summary, food was great and reasonably-priced, and the atmosphere was pleasant. The only negative aspect of the restaurant is that each time we've visited we've been surprised at how early they close. The restaurant seems clear at about 10pm (closing at 22h30) - which you realise by the fact that one or two lights are switched off and the sushi chef cleans up his station and leaves for the evening. Very subtle guys. ;)