I'm very satisfied with the Mumbi holder. The suction cup is very strong and sucking reliably on the disc, no matter if in the dead of winter or roaring heat in summer. The handling could not be better. Phone fooled and push both clamps up and down. To open simply press the RELEASE BUTTON. Done :)
I would never buy a device-specific holder. This one is enough and any other device that I should buy is compatible to.