Just a personal opinion about these toys.
Max - loud and difficult to clean, but works very well both hands free and for stroking. As close to a sure thing for coming as there can be. And will be very intense
Calor - the heating is a bit of a novelty, as it has to be charging to do this. Very good for stroking and the depth controlling the vibes to some extent is interesting. I can’t come hands free with this, though possibly for edging it could work. Clean up is easy.
Gush - IMO better for hands free than stroking. I’m the right controller’s hands (fingers 😂) can edge, milk or make you cum slowly or quickly. Clean up is very easy, and it’s quiet, especially when compared to Max.
Max and Calor can also sync with Nora or Max to give long distance sex. The direct impact of your movement on another person’s toy can be interesting, though the subtlety of control with the app (or portal) is lost to some extent.