The differences lie only in the housing colours and the scope of delivery of the brushes and cleaning agents.
However, I would only buy the new "CrossWave® Edge™" models. Here, the brush drive has been redesigned so that the brush cleans right up to the edge.
Unfortunately, only the new models with a rechargeable battery are currently available at Galaxus. However, I would always go for the corded versions. These wet vacuum cleaners require a lot of energy, which a rechargeable battery can only supply for a very short time. The corded models are also significantly cheaper.