My point is simply that You cannot compare the IR training in Busy Uk airspace with the 'empty' uncluttered skys over the majority of the US and unless you happen to know somebody with an N Reg you WILL have to get a conversion.
I was in Florida which has an awful lot of traffic...I don't know the actual numbers but my impression was the most of the airports we were using handled a lot more traffic compared to say an airport like Bournemouth which handles a lot of IR training. On some frequencies the talk was quite literally non stop.
You are of course right about the N reg and the current N reg situation could change for the worse in the future.