[axytol]

That's a good list of reasons, however it seems the biggest concern is if you run a dedicated DNS service on your network.

For a simple home network setup, as long as naming conflicts can be managed, it looks like mDNS is quite handy.

On a side note, I find .local to be best suited for the purpose, since from the language perspective it's easier on international users than .localhost

The newly proposed .internal comes close, but .local still looks more semantically flexible or maybe this is a cognitive bias of mine.