*Edit* This is based purely on a smallish aircraft though, so it might not be reflective of the bigger picture.
Going into somewhere like Gatwick, if you follow the papi indication on the way down, you will find that your glide slope indication goes far too high. If you follow the ILS indication below minima you'll see that at 150 feet or so, you hit 3 red lights.
It's an interesting point, as obviously we are all taught to follow the papi indications on the way down, but there are many airports out there whereby if you follow the indication, by the time you have flared, you will be outside the TDZ.
Now, my question would be if you were doing a Cat II/Cat III landing, and with the autopilot disconnected at MUH, what the indication on the PAPIs would be? We did a practice Cat II into an airport recently, and when we came out of the simulated approach at 100 feet RH, the PAPIs were showing 3 red and 1 white.
I can't help but feel that maybe some papi bars out there are configured for the fuller figured aircraft...
I might of course be totally wrong though!