I like Rocabar a little more than most on this forum, but it does seem to be the masculine Hermes scent with the smallest following. I think the most common complaint is simply that it's just not as exciting or daring as the other Hermes scents.
According to OzMoz the note pyramid is:
Topnotes: bergamot, lemon, coriander, artemesia
Midnotes: cardamom, violet, orris, carnation
Basenotes: patchouli, benzoin, vanilla, oakmoss
But the description in the paragraph above the note pyramid says something like fir, cedar, and cypress giving way to vanilla and resin. The scent is described as evoking a horseback ride in the forest, and that the scent is built like a tree, with the topnotes evoking the leaves, the midnotes the woody trunk and limbs, and the basenotes the earthy roots. I agree that there's something outdoorsy about it.
Anyway, the previous posters have said it pretty well. It starts out with lemon and bergamot, but to me also has a pine or cedar character. This citrusy, piney sort of smell is balanced by a balsamic vanilla sweetness and rounded out by the foral components. It is creamy smooth, not harsh at all.
The topnotes seem almost minty to me, and the whole opening reminds me of a combination of hard mint candy, pine resin, and a bit of vanilla.
It does get a little sweet in the drydown, but it's not a cloying sweetness. That aromatic, balsamic, resinous character is there as a counterbalance. It is sort of a lively, almost fresh sweetness. For some reason it reminds me of Caron's L'Arnachiste, but rounder, and without the odd metal and blood notes.
It lasts a long time on me, but doesn't seem to be a sillage monster. After a while I have to get fairly close to be able to smell it, not burying my head in my arm, but at least getting to within a few inches.
It's a very good scent and I think you'll like it!