I've always resisted it. We buy mostly fresh food and I like to choose my own meat, fish, veg and fruit, I look for the milk, cheese, eggs etc with the longest use by date, all the usual stuff.
Due to family circumstances it would make my life a lot easier if I did it online and had it delivered for a few weeks. I'd probably use Morrisons as they have some brands we particularly like that other supermarkets don't.
Please can I have your experiences of any of the supermarket delivery services, not just Morrisons?