Tried it once, JJ and ordered the delivery for 6.00pm-7.00pm on Sunday evening (they tell you what delivery slots are available) They then rang and said unfortunately they couldn't deliver till 10.00 am on Monday. We both work so that was not an option and we cancelled. Had we wanted a Saturday or Friday delivery, the chances are we could have accommodated a change of time.
Would try it again though. Supermarkets are hellish this time of year and I'm a compulsive impulse buyer so on-line shopping would solve that, hopefully.
It does take a lot of time though although I suppose once you've done it a few times te operation gets a bit more stream-lined.
You hear stories about people being sent bizarre substitutions though (Lemon Cif, for example not Jif Lemon) and I worry how frozen, frozen food is if you're third or fourth on the delivery route.
Like I say though, I'd give it another go.