>I used to be 100% DSN-less connections advocate until I deployed an application to a group that had different versions of Oracle drivers installed that of course had slightly different driver names. When you use a DSN-less connection string, the name of the driver used in the string has to be an exact match of a driver installed on that machine.
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>The biggest pro of a DSN is you specify which driver to use when you create the DSN on the user's PC. Then all you have to do is make sure the the user creates the exact same DSN name that your application's connection is using.

This can be solved by composing the connection string from user's local settings... i.e. the driver name should then be something that is set for each user. Which is a hassle, of course, as it's more work and more reasons why it would work perfectly on all boxes but one... Even worse, it's a setting you may not need to touch for years, and then it would just stop working.

Maybe a way out of this would be to have a file DSN, which is simply a connection string in a text file, and the app would just read it once and use it thereafter. Then the network guy would be in charge of maintaining it.