I haven't had any reason to ask for anything from a EWR or IAH based concierge but I'd say in about 8 of my last 10 flights leaving the US in the past few years they did come around and introduce themselves at least.

On the other side of the ocean the lady working LHR (I forget her name) is awesome. I met her at check-in and she came around making bag tags for everyone flying BF while we were in line. This was the first time I've been offered these-- and I've been back and forth a lot in the past few years.

I've also had great experiences with the DUB based crews.