I am one of those who used an IMCR extensively and regularly and upgraded to a IR to get access to class A. In my experience the issue is not the level of qualification, it's the currency and the confidence that brings.
I could have done all the things I do with my IR with my IMCR because I do it a lot, so my flight planning, RT and aircraft operation are all reasonably confident.
The big secret in long distance light aircraft travel is that VFR is hard, difficult and complicated and IFR isn't.
Whatever debate takes place on this the fundamental issue is this. In a climate where the weather is not all that predictable an accessible and affordable proper IMC qualification that permits travel under IFR in IMC and includes the ability to use approach procedures to get back safely to the ground is a safety essential not an optional extra.
Knowing how to use the OBS facility on a GPS is a critical requirement too.