I have used both tesco and asda and do my shopping every week with one of them.
they both have pros and cons but who ever i use i find it far easier than going to the shop myself. Chloe is usually fine, i just find it a complete hassle, packing, unpacking, pushing the trolley to car, invariably in the rain etc.
we also find we can control our spending better as you know what the cost will be and can see it adding up and can change your mind easier!
as for dates on things, espically asda. i recently was working in asda and i have to say they take the home shopping stuff from the back of the shelves so it should be the longest date available, however some fresh stuff will always be short on date so it's not necessaily their fault.
as others have said you can refuse stuff you don't want, can change your mind when you see something etc. all have been good at refunding. asda for example, delivered me some eggs which one time only broke, the driver refunded me but only one out of the 6 was broken so i got to keep the other 5 but not pay for them!
you can refuse substitutuions when you order online. i like asda cos you nearly always get a more expensive product and not pay the difference. i've also had quite a few e-vouchers for free delivery from them when i have had to complain, but on the whole good service.
sainsburys and ocado don't deliver in my area so can't choose them but their prices for food are too high for me anyway!!
we love on-line shopping. we book our slots 3 wks in advance so get the slot we want on the most convienient day!!
Lara xx