Not so much Dell, it's the techs they send out.

I have had a few times I needed repair and the parts where always here the next day.
The tech shows up and acts like he doesn't want to be here and has all kinds of issues where he has to leave. He actually tells me when he calls to setup a appointment that he is just sooooo busy and tries to setup a time that is convenant for him and not me.
Unfortunately Dell has a contract with a company who hires these local techs, so the customer has no choice and has to take what he gets.
We pay extra for the warranty and should be getting a good service for our money, but from my experience we are not. it's always hi ho Silver and a cloud of dust and I don't think the guy really cares if the problem is fixed or not.
Another thing I don't understand is why the tech that comes out won't leave a business card? Guess he is not real proud of his service.