If you get the chance to try Essence Oud, definitely do. I bought a 10mL mini from eBay before springing for the full bottle from a local vendor.
Although a lot of people here dislike it, I think it's terrific. Smooth, a little sweet, quite floral and has a decent hit of saffron which a lot of other aoud scents shamefully omit.
Great longevity, decent (though not overpowering) sillage. I can't think of a single fragrance to which it smells similar, either.
I think Ferrari have stepped it up when making their Essence range; I'm hanging out for their Leather Essence to make it to Australia.