We very rarely use locale specific stuff. I managed to get the NZ timezone setup using one of those hacks you mentioned, but that only really helps when you ask her "what is the date". You can't (that I know of) set the location/address so weather requests have to be of the form "what is the weather in Christchurch, New Zealand" - i.e. not much use.
What it is very good at is recognising spoken commands. Regardless of our Kiwi accent. We use it a LOT for shopping lists, Spotify/music, and home automation stuff. It is a great little speaker and integration with Spotify is now much tighter - you setup the Echo to use Spotify as the primary music service and then it is simply a matter of saying "Alexa, play some Foo Fighters" and away she goes.
Her ability to recognise commands from across the room is quite incredible. She doesn't get things right 100% of course, but she has a much higher hit rate than I ever imagined.
And once you integrate with something like openHAB using HA-Bridge (effectively a Hue bridge emulator) you can turn on/off anything you have automated. We use this heaps for turning the TV on and off, coffee machine, garage door, lights etc. Really is more than a gimmick - it is actually very useful. All of this is completely independent of the locale settings so really has no bearing.


