having a FAA PPL will....
enable you to fly ANY N-reg heli under 12,500lbs - no need for costly JAA type ratings
in order to keep you licence current it means you will only have to do a FAA biannual flight review ("BFR") every 2 years. but if you fly the R22 or R44 you will be subject to the restrictions of SFAR73
see
here
it means you can fly an N-reg at night without a JAA night rating
it means you are subject to the FARs - eg the "90 day passenger carrying rule"
it means you only need a (cheaper) FAA class 3 medical to fly n-reg aircraft. 3rd class medicals are also valid for longer than CAA class 2 ones
it means the n-reg aircraft you fly need to adhere to a simpler and cheaper maintenance program than g-reg aircraft