I love my Comma 3X. You just need to have the right expectations. I honestly think their motto of "making driving chill" is a really apt description. I use it in traffic and on the interstate almost all the time, and then on more suburban drives in that 30-40mph range, which is where my Ioniq's HDA doesn't activate. Also IIRC the Ioniq's HDA is map based so very frequently in the city it would just straight up deactivate without any warning due to construction I'm guessing messing with maps. The lateral steering is so much better than the stock LKAS on my car which is jerky and probably scares the living shit out of other drivers. HDA2 is probably a 4/10, Comma is probably an 8/10 in terms of just general driver experience. I've done multiple long (150mi+) drives where I don't touch the wheel for nearly 95% of the trip.
The one thing I worry about though is that they really were promising a lot with the new MLSIM training architecture, and consensus (and my own anecdotal experience) is that these newer models have not been great. They've been working on MLSIM for a whiiiiiile now and there really hasn't been any improvement, though I fully endorse why they are going that way and I understand the difficulty of the problem.
I also have the 3x for my Ioniq 5.
Steering is about 25% better than HDA when solely based on lined lanes, but the 3X is able to adapt to situations that the LKA/HDA would just disengage (such as passing through an intersection) or a random car parked on the side of the road.
I routinely use it even on NYC streets and grass parking lots. It's about 80% accurate in avoiding unexpected cars and larger obstacles or following simply a "laid down" grass trail from a previous car in a grass lot or field.
I did buy it expecting results like in the "Taco bell" video -- and was disappointed under those expectations at first, but after a reality check I still decided to keep it and have easily driven 40,000 miles with it since.