No question that the IMC is a must-have and I'm almost inclined to agree that it should be part of the PPL.
However having said that, its not a cheap rating to get and the average immediate post PPL would be well advised to notch up a few more post PPL hours than the minimum requirement.
Why? Well speaking from personal experience I went for the IMC rating only 25 hours post PPL when my altitude keeping and certain other aspects of my flying made getting the initial IMC a bit of a sweat.
However I did get it and have kept it up ever since.
I really wanted to do the JAA/IR but cost and other factors ruled this out.
I do fly IMC but have to be careful that Wx isnt likely to close in too much as we don't have an ILS at our airstrip and the nearest ILS is miles away.
Maneged to keep my IMC skills ./ interest up by doing the FAA/IR in Florida last Feb: also a thoroughly worthwhile exercise>
OK so I don't fly an N reg so its useless in UK. Nah: experience gained getting this (stiff) test made it all worthwhile.
Don't let anyone tell you the FAA/IR is a piece of p*ss.
Safe flying.