The drivers are always extremely polite and helpful. Time slots are better than most supermarket delivery options, the app is the best out there, and it's often on time and all items are present more often than they used to be.
The downside would be the fact that refunds cannot be requested via the app (only via the online website), which is perhaps deliberate to discourage requests, but when a whole carton of something has leaked all over a bag, it shouldn't be a hassle to request a refund.