That's great! Sorry I didn't go back and read through the whole thread. I just remembered that I'm overdue in changing the Feliway diffuser in my living room! Fortunately, I just need one in the living room and that seems to work well for my cat although if I added one to my bedroom, then that would be even better, but I'll stick to just the living room due to the cost.
I've been using Feliway ever since I brought in ResidentCat and was first socializing her, ~2 years ago. One diffuser in each bedroom. I added a diffuser downstairs where NewCat's basecamp is. And I spray around both doors, since she was anxious to want to go outside.
I laugh that I should own stock in Feliway, or that they should invent a whole-house diffuser. I actually wrote to them about it, asking if there was some kind of bulk discount I could get on the stuff, and they said I should speak to my vet, they could arrange some kind of bulk pricing. I will ask about it, because I go through the stuff pretty fast.
I know many say it doesn't work, or they didn't notice any effect, but if one of the diffusers runs out for ResidentCat I notice she does more kind of random anxious grooming. So, for what it's worth, I think it works. If only it calmed ME down!