I have been running this campaign on Roll20 since mid-2020 and it is still going on. I’ve long heard it was one of the best 5th edition campaigns, and now that’s we’ve put the foot to the pedal and ground out a sizeable chunk of the adventure, I would have to agree that it is one of the better ones – if not the best. I never got into the Ravenloft setting in 2nd edition (which I now regret) but I did run Ravenloft I6 several years back (link here) and it was great fun. But Curse of Strahd is a different beast, taking the PCs from 1st to 9th level (more or less) and pitting them not just against Strahd and his deplorable castle of death, but the whole kingdom of Barovia and the myriad NPCs and mysteries enmeshed within. And there are a LOT of NPCs and mysteries.
One of our favorites so far has to be Pidlwick II, the evil Chucky doll. Although the PCs were supposed to meet him much later in the campaign, I loved the picture and idea of the character so much that I transplanted him to Vallaki and included him as part of a Tarroka clue to directly benefit a party member, and used Pidlwick as a permanent ring of regeneration. The player benefiting from P2 loves him so much and would rather have his own PC die than give up the evil doll! Now that is devotion.