Wore Aramis JHL on the left hand/wrist and Guerlain Derby on the right today to compare the two, as I thought from earlier whiffs of each they seemed pretty similar.
Wearing them side by side, the similarity is amazing. They both open similarly with a lemon/bergamot citrus mix on top of a light pepper/unsweet cinnamon background, with the citrus going away during the first 1/2 hour and leaving the peppery cinnamon with a slight floral mix. I kept thinking they are the same frag, except the JHL has slightly more cinnamon. Both have good sillage, and both are still at least 80% strength and maybe 90% after 5 hours.
According to Basenotes, about 1/2 of their notes are the same, spread across the pyramid. Common notes include lemon, bergamot, pimento, rose, sandalwood and patchouli. Derby doesn't list cinnamon, but it sure seems, to me, to be there very faintly. Maybe it has to do with some combination of the pepper, mace, jasmin or leather listed.
I mostly wanted to report that if you are curious about the Guerlain Derby, which isn't as readily available, you might try the Aramis JHL which is available now in the new Aramis Gentlemen's Collection. It's a pretty good deal at $48 for a 3.4 oz bottle.