@porsupah I don't bother with supermarket deliveries any more because I live in walking distance of a Morrisons and a Lidl, but when I did use them I found Sainsbury the best one.
Their supermarkets are hell holes, but their food deliveries had a lot less missing stuff and substitutions.
Also, I always feel ripped off when paying a fiver for Ocado delivery when their warehouse is half a mile away. Why should I pay the same as someone 50 miles away :p