Indeed
Its akin to a new born challenging Linford Christy (
You ask how hard it is?
The best way to tell you is to unashamedly admit that I cried when I got home after pasing the IRT, this was after three and a 1/2 months of u/s aircraft and bad weather and oodles of dosh.
PS I was entitled to unapproved training as well.
Do an IMC course as an intro and do some challenging Hourbuilding.
Keygrip is correct about the FAA IR, I still believe an FAA IR converts directly to a CAA imc rating and an IMC
and a FAA IR might entitle you to some RHS seat time in something like a Citation II. Flying in th USA is ace fun although I think its a bit different now from what it used to be...
All the best with it....