Perry,
We do not spec the efficiency for the LDOs at 10mA. I can look for some data to support a good hypothesis but, if you order an EVM from our store that will probably be the fastest and most satisfying answer for you. You can order here: http://www.ti.com/tool/tps650250evm-447#buy
An efficiency test is pretty simple and quick. You can follow this blog for any additional help: http://e2e.ti.com/blogs_/b/powerhouse/archive/2013/04/08/draft-blog-from-bob-hanrahan.aspx
-Bob made a really nice video showing the test procedure at the bottom. Efficiency