I think it's just that Asda (at least ours) has been getting progressively worse over the last couple of years (maybe longer) and it is a horrible place to go, with regular shoplifting that makes you feel uneasy, to staff that look like they hate being there even more than you. Staff post their experiences online, which seems to back up all the theories about how the company is going - which isn't good.
But Waitrose is indeed a nice place to shop. Like Aldi, there are limited numbers of product lines that makes shopping easier - but prices on many products are high (yet they do offers that can and often do undercut Tesco, Sainsbury's and others). If you shop with your phone/scanner, you can see the deals even if they're not correctly labelled - but I do find that when you get a random rescan, staff often aren't logged in to the appropriate app and then make you wait ages to be able to check the one or two items requested. But that's a first world problem.
But Waitrose is indeed a nice place to shop. Like Aldi, there are limited numbers of product lines that makes shopping easier - but prices on many products are high (yet they do offers that can and often do undercut Tesco, Sainsbury's and others). If you shop with your phone/scanner, you can see the deals even if they're not correctly labelled - but I do find that when you get a random rescan, staff often aren't logged in to the appropriate app and then make you wait ages to be able to check the one or two items requested. But that's a first world problem.