I use the blue box for about a year and I really love the portability and the fact that I can easily connect my dawdles setup !
The UI is super easy to use and you can add a midi controller for the faders, like notation launchkontrol Xl. The fader response curve can be improved though, they give frequent firmware updates on their website so this will be improved soon.
I use it with multiples synthesisers and drum machine, but I quickly encountered noise issues that are quite annoying especially because I use a master compressor after it and it just raised the noise floor a lot. You can also notice it if you use the internal compressor.
So my opinion on this price range the noise issue shouldn’t be a problem.
I am dealing with it in live situation, it is not so audible when the music is playing but you can really feel a big huuum if no machine plays.
This is very likely to be linked to the USB power thingy, I tried to plug the same set up to my Arturia fuse studio and I did not get those noises.
I will try soon to use like a DI box with noise cancelling to try to lift this ground noise, let’s see.
I also love the internal effects reverb and delay sound great and rooting possibilities are amazing, but the noise makes me considering a less portable alternative.
An upgrade Mk2 solving noise issue would be great