I think everyone's missing the point of the DVR. The biggest benefit of the DVR, IMO, is the ability to use the IPE (In Place Element) structure to read write data. Using the structure provides exclusive lock to the data access AND eliminates copies. Doing this with a SEQ (Single element queue) is a PITA and requires a whole bunch of lock and unlock code. On top of that you create extra data copies when you read the queue element.
Data Value Reference Read / Write Element Border Node