I would agree with this. Its all down to how good the individual driver who is dealing with your delivery, is. Some drivers are a little dim and don't give a damn about making deliveries. Others want to deliver the parcel no matter what and will go the extra mile to successfully deliver the item. As an example, my local Parcelforce driver, attempted to deliver the same parcel 3 times in a single day, to me. He succeeded the 3rd time.
I've not had any problems with DPD, but have had some serious issues with CityLink.
Bad Courier - CityLink
One example was when I ordered a projector screen from Germany. The seller sent the screen on time.
A week later, I still hadnt received anything. Not even a note through my letterbox.
I contacted the seller, who in turn contacted the German courier, who in turn contacted CityLink, UK. The seller sent me a phone number to find out what was going on. Upon phoning them, they said they attempted delivery twice (liers). At this point I said, can you deliver tomorrow? What now ensued were a series of phone-calls and excuses why they couldn't deliver it. In the end it transpired that they had ran over the screen with a truck. The package was so damaged that they too embarrassed to attempt to deliver it to me. Rather than tell me the truth they made up a lot of stories which cost me another week or so.
In the end the seller had to send me another screen which arrived within 2-3 days (as scheduled).
The Best Service - Royal Mail/Parcelforce
Once I was awaiting a package. The seller had inadvertantly forgotten to write down a postcode or door number - hey only wrote down my name and street name...nothing else.
The package arrived a day later than scheduled, with a note saying, "In future write down the full address". I was in awe, given that Royal Mail managed to track down my address and deliver the parcel to me, using only my name. I'm positive that had Citylink or DPD been dealing with this parcel, it would've either been sent back to sender OR ended up in the bin.