Why is the file size for 10.1.1 so much larger (33% larger, in face) than 10.1.0? Clearly that can't be simply plugging some security vulnerabilities.
This is a user to user forum. Do you really expect your fellow users to know why the code Adobe produced is larger? On what platform is it larger? Maybe Adobe just created an installer that installers 10.1 and then includes a patcher to patch it to 10.1.1. As we don't have access to the code it is just guesswork.
The downloaded Exe contains full Reader 10.1.0 and a Patch 10.1.1
Together they are ~50MB compressed.
If AIR installer is included into download by Download Manager, it is additional ~15MB