Let me start off first of all by saying that I am a huge fan of vetiver in all forms, and a huge fan of vetiver based fragrances. I find this one very authentic and extremely well made.
The fragrance starts out with a hit of smoky, earthy vetiver and some citrus. I get the cloves and some dark spices (including black pepper) and it really brings out the "dark" aspects of the vetiver root. It is said that perfumer Dominique Ropion, who has done amazing stuff for the Frederic Malle line, used about 25% vetiver absolute when composing this. This makes it the highest concentration of vetiver in a perfume currently available on the market. As a fan of vetiver, this alone made me want to try it.
I am also a huge fan of Guerlain Vetiver, but this one is slightly different. Where that one was a balance between vetiver and citrus (ie lemon), this one is a very dark, earthy, rooty type. It showcases the whole root of the plant, almost as it the earth is still clinging to it. I also compare this one to Lalique Encre Noir, but there are noticable differences. Although they are similar in "feeling" or "tone", the Lalique is sweeter, and less natural. This one is greener and earthier all the way.
Vetiver Extraordinaire hits you with a strong blast of vetiver root and says "here, deal with it". You have no choice but to accept this in-your-face type of vetiver.
As for me, I would consider purchasing, but only because I am a die hard vetiver fan. This one I think is a vetiver fan's vetiver, there is no compromise. But I must admit that if you are concerned about cost and versatility then there are other options, the Guerlain, Tom Ford version and the Lalique are all great choices, so don't feel under pressure to get this. But if you want it done right, then try this out. My only drawback is that it doesn't last the whole length of my day, even though the concentration is high. Still for now, I would only buy this if I had the money to spend on it. Otherwise I can still stick with what I already know.