I found OREX might be better choice because of three reasons:
1. Better weight lose. High single digit comparing with ARNA's 5%.
2. Smaller cap.
3. More recent insider buying:
OREX Insider trading transactions, insider planned sales - MSN Money. Their purchase price is around 7.7-8.00. ARNA's insider purchase is around 2-3.
I have plenty of ARNA, might switch to OREX soon. Jia, what do you think? Just ask your opinion, nothing to do with money matter...
Plus, ARNA got a big drop during the last release...