Folks,
I will assume, of course, that Spoon is making a little joke above, because no one who needs a FFM gives a rat's patoot whether it is DIR, RID, or any other set of initials.
A FFM is a tool, to be employed as needed, and the reasons are many, including using UW comms, doing IWR, protecting the face from cold or contaminated water, or, in just plain recreational scuba, enjoying the picture window view.
Once you learn to get the face-seal set properly, and become relaxed in the use of the mask, you will find that you use little or no more gas than you would with a standard mask and mouthpiece. I have a Divator MkII, a Widolf, and two Ocean Reefs. I have used the Divator for 14 years now, the Widolf for 5, and the Ocean Reefs for 5.
They do require a little extra practice and preparation to use, but, shall we say, it is by no means rocket science.
As Mr. Natural always said: "Get the right tool for the Job, Kids!" :doctor: