We have a client who insisted on using a .house domain. It kept triggering alerts on our uptime monitoring service with DNS errors, so we had to reduce the sensitivity of that specific test.

We also had a client who had to change their TLD from .healthcare to .org.uk because (a) people were confused because they didn't understand that there are all these new TLDs and kept adding .co.uk, .org etc and (b) some NHS systems in the UK (one of their target audiences) refused to accept emails that finished with .healthcare, saying that it was a malformed email address.

I think in the vast majority of cases these new TLDs aren't worth it until the general population's understanding catches up. I still advise clients to use www rather than a plain domain name for websites, because I've come across a significant minority of people who need that "www" as a clear signal that it's a website.