I've used both. Not regularly but as an occasional treat, especially when we are having a a self-catering holiday.
Generally waitrose has a wider delivery area - many UK holiday spots are not in ocado's service area but will be in-range for waitrose.
Ocado will only do packets of fruit and veg rather than being able to get loose stuff. Ditto bread - you can only get plastic-wrapped bread from ocado, not the loose stuff produced in in-store bakeries.
Waitrose don't deliver nationally we used Waitrose before moving out to the country. Loved their delivery service but cant get it here yet, we only have a local little Waitrose. Tried Ocado 3 times and each time there was a problem. Never again.
People still assume that Ocado and Waitrose are the same company. Originally Ocado used to only sell Waitrose products. They are 2 separate companies. Ocado have their own warehouses where their products come from and can sell products from whatever companies they want. Like a normal supermarket but on wheels.
Having used both, I'd say Ocado wins hands down. Comes from a warehouse so much longer dates and fewer subs. Price matches Tesco. Can get WR and their own own-label (so a good choice of OL things). Access to lots of interesting and unusual products that struggle to get listings in the supermarkets. Really efficient and prompt delivery. And - importantly - MUCH easier to shop. The WR website is hideous, but the Ocado app is a dream to shop with.
I use both At Waitrose there is a minimum spend of £60 for free delivery Ocado have a minimum £40 for delivery and there is a charge. You can get a smart pass from Ocado which reduces this Ocado is delivered from a warehouse so very little subs Waitrose is from local store. At Waitrose you can order meat/fish from butcher and fish counters which is fresh and tailored to what you request Same with bread..you can order from their in store bakery and fruit and veg the same Ocado do not have this option. If I order fish from Waitrose it is from the fish counter and packaged and priced accordingly. From Ocado it is pre packed
You can order meat and fish from the 'counter' with Ocado (ie - not pre-packed, but cut to your chosen weight). Sadly not bread though. There are always discount codes for a first shop, or if you know someone who uses them, get them to recommend you, and you'll both get a discount. Once you've done your first shop, they will almost certainly offer you a free or very cheap delivery pass for a year.
We've been having weekly deliveries from Ocado for years. It's not true that you can only get plastic wrapped bread. We always order fresh bread e.g Gail's Bakery. I have found that Ocado delivers to more places. We have also order meat from the deli counter which is not present packed. It is a long time since I ordered from Waitrose but when I did they were more restrictive with delivery slots. Ocado give a 1 hour slot.