I agree about DPD, they are spot on.
I had a pair of drive shafts delivered by them and you can track the exact location of the courier on google maps. I saw on the map he had turned into my road so i was able to go and open the front door just as he pulled up. I couldn't believe how accurate it was.
Unfortunately the driveshafts were wrong so they returned the next day at the exact time they said they would with the correct shafts and took the others with him.
Nice bloke and even stopped for a quick chat 
My Hermes are fine for me unless something gets damaged and then they don't want to help. I think the problem is that their delivery network comprises of mr Joe Bloggs in his Vauxhall Zafira instead of a crew of uniformed drivers in sign written vans meaning that stuff seems to be harder to track and seemingly impossible to resolve when things go missing.
But then they are very cheap so sometimes worth the risk on large low value items.
