Amber Aoud has a very nice prominent note (sorry, I know it sounds obvious but it really smells like Amber attar oils that I've experienced before). It is sweet and lasts for quite some time.
Crystal Aoud is rose based. Quite a sharp rose. Reminded me of Heeley's Agarwoud; I prefer the rose in Heeley.
Based on my limited wearings of the two Roja Doves at this point in time I prefer Amber Aoud.