On balance, Asda have made me happy for their simple booking process and ability to add multiple cards (a feature that was not available at the time of purchase when using Sainsburys). Not having this meant we would have to re-enter card details each time as we took it in turns to pay, week by week. There are a lot of good deals on Asda groceries website which take the stress out of popping into the store. A drawback for me is that a lot of products I'm not so interested in are advertised, seemingly at random, throughout my shopping experience (so if I accumulate a favourites list, they will appear here too). This is confusing. I like the way I'm told if i've completed a deal though (for instance if I pick 4 items that enables a particular deal to activate there's a green visual que, rather than a red one). You also have some good summary information prior to buying, in case you've forgotten anything. Overall a less painless way to shop.