I've been ordering my groceries for many years and have tried and tested most of the supermarkets. Ocado is the best by far. They have thought of everything and it is so frustrating and annoying when on the odd occasion I have needed to used a competitors. The things that I love the best are:
The App. I do my groceries shopping on my commute.
The receipt that is sent prior to the delivery been made so if there are substitutes that I don't want and my husband is taking the delivery I can tell him what to return. And if there is something missing I have time to make other arrangements. Most of the time everything is available.
One hour slots.
Delivery staff are fabulous.
Range of products means that I don't have to go to department store to get gifts.