I bought it to work with iOS (iPad Air 4), first of all with GarageBand. I read about MFi and that you can control GarageBand with it. Well, you can.. Sort of. Transport buttons seems to work on some of the factory presets, but knobs generally don't work with GarageBand (only Volume works). I was looking for help in IK Support but so far they only asked if I have latest firmware and drivers on my Mac/PC (yes, I am not using it with Mac not PC, but with iOS, so it won't help me at all). So if you, like me, read on the product website that this Keys were made specially for iOS devices and controls DAW including GarageBand - be aware, it's only partially true.
Stripes are ok, I think it's possible to use it while playing, but tone stripe sometimes don't get back to neutral, central position. Not sure why. Pads are quite ok, but I found I can't get full velocity of MIDI instrument when I press pads (in comparison to what is possible with touchscreen of my tablet).
Keybed for me is super comfortable, I didn't expect anything more. And full size of the keys is something I wanted in my MIDI Controller, so I like it. I don't find it loud as well.
It's small, I like how it fits on my small bedroom desk. About interface: I've tested it with range of guitars so far and it does work with passive instruments, doesn't work with preamped signal from active bass and electric-acoustic guitar. Additional usb-c cable included in the package.
IPad holder can only stand on the flat surfaces, it's not attached to the Keys anyway and it can hold iPad only without a protective case.
Overall, if you're looking for a bunch of Keys to work with your DAW on the iPad it will make the job very well. If you're looking forward to use more of its possibilities... You probably should also use different DAW than GarageBand. And it may work then...
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IK Multimedia Support informed it should not work with iOS as I expected. There is no possibility to control iOS GarageBand with the iRig Keys I/O.