When I did the IMC course it seemed to me to be like doing the PPL course again, only properly. In this regard, I'd say that this is a much better way of 'hours building' than just boring holes in the sky. It's a bit more expensive than just renting for the equivalent number of hours, but much better value for money. I'd do the night rating, too, for similar reasons (as well as being great fun, a wonderful experience, enhancing skills, etc).
I think the IMC rating is here to stay, the only problem seems to be we're losing instructors capable of teaching it.
TOO