Just popped in here because it looks like the thread will be deleted from the PF forum.
As someone who has gone down the FAA PPL/IR route, including the huge cost and hassle of putting the plane on N, let me say that the #1 problem with the JAA IR isn't the flying requirement. Those that are flying IFR privately, will be aircraft owners (or part owners) and of something pretty decent. To most of them, the cost of 50 hrs of flying isn't an issue. I know a fair few FAA PPL/IR holders that do 5x to 10x that every year, around Europe on business.
It is the ground school, the time it takes to do it, and the way it is designed for people with plenty of time, to be run through in a massive show-what-you-can-memorise swatting up exercise. Those who can afford to fly IFR are people with real work to do, and they can't find the 2 years (my estimate) it would take to do it.
A pretty comprehensive revamp of the ground school is therefore called for.
As for flying into Heathrow, what is the big deal? An RV ILS is the easiest thing possible. An IMCR holder, who flies IFR often and is convincingly quick on the radio, and has had a day's ground school on SIDs/STARs (which are themselves a very simple concept) could do that safely enough. Look at the number of fresh JAA IR holders who post questions all over the place asking how to do an airways flight. What exactly did they learn, in that massive swatting-up exercise? By all accounts from ATC staff I've spoken to, there are plenty of really ropey ATPs, from all over the world but particularly some 3rd world countries, flying into Heathrow daily. It's only if an engine is about to fall off does the CAA jump on them. So, no good saying ICAO requirements aren't good enough for Heathrow.
I wonder how close to the FAA ground school they are likely to get in this review?
However, looking at some of the planes that are N-reg for certification reasons, EASA needs to take FAA certification fully on board also.