I got my JAR multi-engine IR last week. I took it out of Gloucester (but all my training up to the last 10 hours had been in the US).
As for the course content - I'm not particularly familiar with the old IR, but as I understand it, the only significant difference (with the test itself) is that you can be asked to do an assymmetric ILS approach under JAR. In addition you now have to do climbing and descending on partial panel, as part of the GH section (not particularly difficult).