Not used that particular one, but passive mixers are generally all the same, you lose a fair bit of gain which gets worse the more devices you have connected, often though it is not a problem, for example if recording you can make up the gain on the recorders input. Passive mixers add no noise but can suffer from a bit of crosstalk if the connected devices have different output impedances, but in the case of the 3 devices listed you should be ok.
Thanks for the info. That might become a problem if i wanted to attach other things? I also have a mopho keys, a blofeld, a Tempest and an MS-20. I probably won't use it for those as i also have a Mackie mixer. It's purely for jamming with small devices in the living room...
Thanks for telling about this one. It looks very nice, shame about the noise though. I was hoping to avoid an adapter..
I was looking for something just above the Rockstar, e.g. with pan, active.
But in the end, I am now looking for a full mixer, with FX and the ability to record straight to a USB key or something, as well as being a USB audio interface. Still trying to avoid computer as much as possible.