I would even go as far as saying that the R2D Rebreather II is also obsolete!
Here is a lesson in history...
The original debreather concept (Debreather) is an adaptation of the SCUBA debreather but "powered" entirely by the user's via breathing, i.e., no compressed gas. In fact, the Debreather led to the eventual development of a more effective inert gas asphyxiation method: the Exit Bag. So, the Debreather came before the Exit Bag and not before.
According to the research report by R. Ogden, 2010 (my Jan 23rd blog entry): "The debreather appears effective in bringing death through oxygen depletion, BUT it also demands third-party assistance...[and as such] is no longer in use." The report further highlights an attempt to improve the Debreather with powered circulation (Spartacus III) which required the user to don a plastic bag. That device was never commercialized with the advent of the use of compressed gas for CBT.
In short, the R2D Rebreather II is an attempt to reincarnate a failed device.