I use it a fair bit but it can be hit and miss, plus location plays a big part too. Pre Covid I used it a lot when I had to travel more for work, and (obviously) London was excellent for it at the time.
There is a Harvester near me which can be excellent or underwhelming. They also have a tendency to cancel fairy last minute, which I’m surprised is allowed. In all fairness, last time it was on my partners phone and she hadn’t seen it until late i.e. I was there, and they still honoured it but just made it up with different items.
Either way, it’s a great concept and a good one to support.