I took mine off (1996 Disco XS), because i didn't like them. I found nothing of major concern, just years worth of gunk and crud.
I spent an afternoon washing the area, then rubbing it down a little and applying some white Hammorite to where the plastic guards would be. This looked crap without the plastic guards, so I had to buy some new ones after destroying the old ones taking them off.
Some people on here have quoted daft money (£150-£160) for a full set. I got mine either from Paddocks or my local LR main dealer for about half of that, (sorry, can't remember which one it was now).
Still not cheap I suppose, but it's now another area of the car that is protected against rust.