To add confusion for all you foreign johnnys it's now not an IMC rating but an IR(R) rating...
. Although it's exactly the same as the IMC rating. As BP says the main differences between the IR(R) and the full fat IR is that the IR(R) foesn't allow flight in class A and the
recommended minima are 600' for a non precision approach and 500' for a precision.
Is it any use? Oh yes. If you've never flown in the UK's maritime temperate climate then it's the best thing since sliced bread. Plus mine cost me about £2300 all in cf a full IR which is about 4 trillion quid.