When I create a new blog from the "Site Admin > Blogs > Add A Blog" feature it creates the following user meta....
21708 5079 wp_89_capabilities a:1:{s:13:"administrator";b:1;}
21709 5079 wp_89_user_level 10
When I navigate to the "Site Admin > Blogs > Edit (blog 89)" and set the newly created admin user to editor the user meta looks like
21708 5079 wp_89_capabilities a:1:{s:6:"editor";b:1;}
21709 5079 wp_89_user_level 10
Apparently even though the user's role was changed to Editor, the user level stays at 10. According to http://codex.wordpress.org/Roles_and_Capabilities#Editor the editor should only receive 7 access.
User levels are around for backward compatibility with plug-ins, but to my knowledge do not affect the core WordPress functionality anymore.