We made the decision to move to DPD as our primary courier (rather than the Royal Mail) about a month ago and I have to say it is proving to be a really good decision.
Delivery is the one thing we cannot, as a business, directly control but which is fundamental to the customer experience. We can have the finest macarons in the world but if they are delayed, or even worse lost, en-route to our customer then it makes no difference.
Last Christmas was frankly a dreadful experience for us using the Royal Mail. We had issues with 15% or more of all our parcels and spent most of the early part of January apologising and remediating, and we have no interest in repeating that experience.
DPD may be more expensive (they are) but they know where every parcel is at any time, they take a photo of every delivery, with geolocation coordinates and if there is an issue you can pick up the phone and connect through to customer services in a few rings. Oh, and they come to your premises and pick up as well.
***** UPDATE *****
We set out over 1000 parcels in the final run up to Christmas and ended up having issues with just 3.
Well done DPD.