I've tried Borneo Zazen which I believe is a reformulation of Zen (not sure what the exact difference is) and I love it. Like Bryan said it is very jasmine/floral centric, but I prefer (I'm about to commit blasphemy here) oud based attars rather than pure oud oils, and I think the oud and jasmine blend is brilliant. Ensar did something similar with Monsieur Oud, which is a oud and frangipani blend. Both of them I would say are his best creations.
I ordered Zen straight away, as I had ordered a sample of Borneo Zazen and waited for a sale to order a full size, but by then it was out of stock and I've been on the hunt for it ever since.