The Saris H3 is the closest to the Kickr. It’s the best if you do high watt work or Zwift non-planned workouts. It does suck at going high watt to low watt during a workout- you can spin it up and wait 2-3min for it to spin down. You need to be in the lowest gear you can get away with. The freehub is also loud.
The Tacx doesn’t have any flywheel, and the feel is not realistic IMO. The resistance is 360 without any light spots, so you feel like you’re climbing all the time. The resistance changes are also not natural. It’s good if you’re a climber though.