bug: changing an option on a select input on any widget in the widget admin produces a "Object * has no method 'apply'" error
vanilla install of WP 3.6, page builder 1.2.11, no other plugins installed, default theme.
pick any widget that has a dropdown select option (custom menu widget for example), change the selection and the error is produced. I tried this in the Widget admin, haven't checked inside the post editor.
Also, widgets with radio element options don't have their values populated and checked properly when used inside the page builder.