Of course you could go the way that we in Oz did some years ago - decommission ALL PAR installations in favour of ILS.
I was trained to fly PAR approaches as a young sprog on pilot course, and some years later trained others to do the same. Can't speak highly enough of the PAR as an approach aid (except the piece of kit that's been described above - sounds dodgy!
) mostly because (as mentioned above) it's NOT a pilot interpreted procedure. Got to be a plus when trying to land an aircraft with an emergency in c**p weather. Just do as I'm told by the friendly controller and hey presto - out I pop at 100FT above the runway on centreline.
Our ILSs' are only CAT 1 - ie 200FT DA, and their serviceability is just as good (or bad, whichever way you look at it) as the PAR installations were.
All in the name of saving money though..................