Reading about RVSM, I noted the exemption for "state aircraft." This is summarize in wikipedia as
"State aircraft", which includes aircraft used in military, customs and police service, are exempted from the requirement to be RVSM approved. Participating states have been requested, however, to adapt their state aircraft for RVSM approval, to the extent possible, and especially those aircraft used for General Air Traffic (GAT).
The topic of RVSM has also been addressed here before. My question is specifically whether a particular United States "state" aircraft or mission regularly makes use of that exemption (INCONUS or OCONUS.) I would imagine that in order to avoid burdening ATC / ATS, military and government aircraft would try to operate above and below RVSM airspace as much as possible but perhaps there is an example of a case where that is not true?
I am particularly interested in knowing not only which aircraft (or models of aircraft) regularly make use of this exemption but what the justification is for doing so. After all, if FAA literature is true, flying a state aircraft at these altitude halves the capacity of the airspace. Would fuel economy be a sufficient argument?
I'm also curious about the "manufacturer" exemption. I'm sure that operating NON-RVSM would not be included on a Letter of Intent without good reason. What would those good reasons be? Testing new RVSM equipment? :)