I'm a little bit amazed sometimes at the feelings around the metrification issue. I wonder if they went through the same scope of debate when they stopped using leagues and cubits?

In terms of the CATs, they are a guide, so that someone considering a race gets a feel for the degree of difficulty. But that is it purely a guide as no one can really prepare you for the real thing until you go and do it.
You can have a look at race record etc to get a feel for how tough a course is.

I agree with FellHound on the A+

I'm a little torn on the PPP. It does have a special place in fell running and I'm sure that the changes to the route, as much for environmental issues as anything, have lead to the race being a little longer but with the same ascent and taken it from technically being an A to a B.

If you had it as CP to CP, then it would become an A and I think that should be perhaps the way a race is categorised as it clearly does not make it any easier by adding a couple of miles of relatively flat running.