I have decided and requested to transfer part of my OA account to SA to generate higher interest. When I mentioned this to my wife, I got "..." look. LOL. Why do I decide to do the transfer? Simple, because the SA interest rate is higher. I think most people is aware the current OA interest is 2.5% and SA is at 4% (guaranteed by Singapore government). But I think there might be some who are not aware that the first $20K in OA and $40K in SA gets an additional 1% interest (I was not aware until I checkout the CPF website recently).
Here's a presentation on CPF by SIAS speaker, Christopher Tan, which I find useful in explaining how CPF works.