Not sure if the situation has changed since this thread started with regards sales in the UK.
I have increasingly seen these used at shows in the UK on American layouts.
It would appear that friends in the US have purchased them on the UK residence behalf and shipped them as presents quoting that they are "Model Railway items". Quite what the UK customs would say if they knew, I am not sure.
Sadly this results in a "High Powered" radio unit being used presumably illegally.
If I read the thread correctly, its the cost of getting a unit that emits radio waves, licenced for use in the EU that is the barrier. Does this mean that a DCC fitted loco has to be certified ? my layout certainly plays havoc with my nearby radio.
Reminds me a bit of the CB radio stuff years ago.
I have resisted on the grounds that my bank manager would not approved.