I've used them about a half dozen times in the last 18 months in Los Angeles. I find the online ordering process slow, probably due to the indexing of items runs counterintuitive to me.
Delivery has always been ontime or slightly early, and the drivers are courteous/helpful.
I try to avoid ordering fresh produce, as I'm too picky. I want bananas and tomatoes to be a certain ripeness, and never buy grapes in a store without trying one from a batch. This is inconvenient to me, as I end up having to go to a store anyway, to get produce.
Along the lines of the produce concern is ordering milk. About half the time the milk they bring is going to expire in five to seven days. I want milk to last 10-14 days from when I buy it, and when I hit the brick and mortar locations have no problem buying that way.
Overall a thumbs up service, with limitations. Give yourself plenty of time to process your order, unless you are highly organized and have a specific list in front of you.