Who will Apple be delivering with?
In my personal experience, "high-value" items have always come to me via DPD. I've had cases and other accessories/cables come via DHL/UKMail, UPS, Royal Mail and DPD before.
But come delivery day, you'll find it varies between DPD and DHL/UKMail - most probably to balance out the high volume of shipments, but might be down to regional coverage too. DPD is the best though.