As I recall, a part of the rationale behind the introduction of the CRI in the UK was to give some official backing to the PFA's system of having pilots experienced on unusual types of a/c helping out less experienced people. It seems to have moved away from that original concept (but see below ref AOPA).
I did the SEP CRI before I embarked upon the FI(R) for a number of reasons. firstly, I didn't have time to do the full FI, Secondly being in a 'syndicate' I wanted to help out newer-qualified pilots from a position of instructional expertise and thirdly to see if I would 'take' to instruction before duing the course. Although the CRI course seems modest in content, done by the right person it can give a great insight to instructional technique. I did mine with the same person with whom I ultimately did my FIC.
Now I've got the restriction removed, I've allowed the CRI to lapse. I no longer see that it offers anything over and above the unrestricted FI.
I read that AOPA are setting up a 'mentoring' scheme. Surely all those putting themselves forward as such will need to do the CRI course and pass the test?? (Or so you'd think!!!)
The Odd One