What I like about using GET (and, to some extent, POST) is that it makes it trivial to test your API in a browser while developing it. Just paste in the URL and you get the raw response, fetch time analysis, and everything else the Chrome developer tools provide you.
I'd add that one of the best features of XHR Poster is that it uses your cookies and any authentication you've already performed in Chrome when sending the requests.
I had to build an API that lived inside a system with entirely too many authentication/cookie checks and using curl was becoming too awkward for testing, this saved me a lot of time.
This shouldn't matter much, but it does.