For the number of post/parcels I get from Royal Mail, they do a pretty good job - only one time when they didn't bother to put the red card through my door, but had the letter at the sorting office (it was festival tickets, the festival was only 6 days away and I took a gamble and went there on the off chance).

DHL on the other hand left a parcel at the local shop, didnt tell me that they had been, and on their tracking system it came up as 'delivered and signed for'. It took 2 days of phone calls to track that one down.