SQL writes:
There's every reason in the world to use it, including that you don't have to worry about the UI changing by surprise at 3AM.
SQL
Yes, you just have to worry that query.php is replaced with api.php, which may be then replaced with something else. And also, I went through the mediawiki-api archives and found about 9 breaking changes for API. Pretty stable, isn't it? :) --vvv