Noise and squeaky wheels
My iPhone was pre-ordered from Vodafone, with an upgrade price that was more attractive than their new customer price (£75 for 32GB 3GS on £40/month contract, vs. £149 on their website). I pre-ordered the day the email went out saying they were available, the customer rep was extremely polite and helpful, and promised delivery on the 15th Jan.
I got SMS notifications from DPD as the delivery progressed, following SMS notifications of the order (with a glitch which was explained by the rep). The phone was delivered on the 15th despite being in a hard to find house covered in snow.
There were no issues with the SIM as it was an upgrade; Apple include a tool for opening the SIM door.
The only disappointment is the lack of Visual Voicemail - I'd hoped to eliminate Vodafone's very determined voicemail calls which can be a bit irritating if you've failed to answer because you're busy, rather than actually away from the phone. Hopefully this will be implemented soon.
I've been with Vodafone since 1996/7, and don't spend a lot with them. So far I'm impressed.
I'd agree that Home Delivery Network are a bit rubbish; I really try to avoid them on the whole. However, Citylink, DPD, DHL and Royal Mail seem not to be inherently flawed, only prone to local issues with some drivers/routes.