Currently there is a built-in profile available for the user agent (user.browser) but not one that returns how Target evaluates a given user agent (and any of the other fields that are used to determine iphones) as a device.
This enhancement request is to have a profile that returns either device or device type.
This would be tremendously useful for the purpose of validation (mbox Trace) and having the ability to troubleshoot any issues related to device identification.