I love what this plugin should do but for me it gives error messages where the Admin Bar was. I unchecked the Admin Bar display for all roles except Admin and Editors, so regular Subscribers shouldn't see anything. It kinda worked in that the Admin Bar didn't appear for Subscribers but instead, the following error message was displayed at the very top of the page.
Warning: in_array() [function.in-array]: Wrong datatype for second argument in /home/xxxxxx/xxxxxx/wp-content/plugins/wp-custom-admin-bar/custom-admin-bar-functions.php on line 89
I've disabled this plugin for now instead of deleting it because I'd still love to use this plugin once the bug gets fixed. Can't find another similar plugin that lets you choose viability by roles.