During our development cycle we often release a number of beta's prior to the final release of a version. These beta versions are released so users can test new features, and to confirm that the basic Drive Bender functionality is as it should be.
However at times there are features added that are difficult to beta test. These are usually low level file system features that 99% of users would not care about (or even know about). By adding them as experimental, we can release these features disabled and have users enable these as needed. After a period of time, most of these features will make it into the product as permanent features and will no longer be listed as experimental.