The FAA IR sounds attractive, but you do need to reregister your aircraft to N reg, and can only fly IR on an N reg. Can a JAR pilot fly an N reg without a restricted FAA licence? You can't cost share in the Uk, which is a real nuisance.
You can however do the FAA IR in the UK..has anybody done that and with whom? I know doing in US is cheaper, but I'd rather learn UK airways and RT, not to mention our wonderful IMC weather.