I have been an Ocado customer for about 6 years. During that time I have had few problems. Their prices are quite keen (especially the flash sales) and they keep their substitutions to a bare minimum. Their drivers are always cheerful and polite and on time , except on the rare occasions when mechanical failure or natural disaster intervene. The reason I have given 4 stars and not five is that I have occasionally had a nonsensical substitution and on two occasions I have had a bad attitude from their call centre. They also went through an annoying phase of charging more for some of their items in the flash sales than they were advertising in the shop proper, but this seems to have stopped now.