Never used either. Although recommended by vets, and animal behaviourists, friends who have tried feliway say it didn't work. Given the choice I would try pet remedy as I have used oils for myself, and find they work well. But don't know about cats. Essential oils are poisonous to cats if ingested. Although in a diffuser, I still wouldn't personally use it long term. It's my personal thinking that oils could still get into the bloodstream via the lungs when breathed in. But I'm probably being too cautious. I myself would use flower remedies.
Julie.