OK, to those who are concern. I can answer my own question.
There are huge price difference between the two. RE seems to be double the price than AO on the market. Besides the price, there are only three differences between the two.
Nose piece stem: RE and AO has different nose piece stem setting. AO seems to fit my face better. But this is a personal preference.
Temples: AO has "AO" logo emboss on the front of temples, no wording on the end of temples. RE...