There is a developer, lets call him John (currently on probationary period) in company(pretty small company approx. 10 persons, 3 developers, one of them works long in this company know business process around and can be consider as Team leader) who didn't want to use any IDE at all(he is using some text editor).
Application this team working on is medium size Java application with Spring Hibernate technology stack and refactoring/adding new features to launch new version of that application in near future. John performance working without IDE on this application is lower then desirable, team leader's (lets call him Bill) assumption is this happens because John is not using IDE. Bill try to persuade John to use IDE, but this idea meets a lot of resistance and main reason is "I want to be in total control of what I am doing, so I need to write all code by myself".
How can Bill convince John to try to use IDE? (considering the fact what Bill already protected John from company owner several complaints about John performance)
Updated: Bill decide to try and convince John one more time if that attempt will be unsuccessful then he won't try to force John to use IDE and rather look at if features promised by John are delivered in time or not. Thanks for a lot of nice answers(Still can't decide which of them is best).