Haken Audio Slim Continuum 46s8x

The synth is very powerful and open door to many different synth techniques. It can recreate any real instruments (strings, wind, percussion, bass, voices...) and it allows to build unique sound using standard and special oscillators (additive, modal, physical, granular...).
It comes with eagenmatrix application. It is like a synth interface program that resemble EMS Synthi A control matrix on steroids. It allows to use formulas to have a deep control of any parameters of the synth. The inputs to the formulas comes from MPE fingerboard. So it gives a high level of expressiveness to the generated sound.
The fingerboard can be used as MPE controller to another hardware or software synthesizer.
The synth can process audio. The audio input should be digital (spdif).
It is possible to use synth without computer but in order to have a deep control of the parameters or to create a patch from scratch it needs to be connected to eagenmatrix.
Unfortunately Continuum has no knobs, faders... So midi controller is a great addition to it but I wish there were few build-in faders/knobs.
Overall the synth is great for sound designer or experimental or academical music. It comes with many patches that I think is very important to study in order to learn the synth.

The Haken Continuum is definitely an A-grade instrument. I've only scratched the surface of what's possible thus far, but I found the fingerboard to be immediately intuitive (albeit requiring practice). The synth engine is a bit less user-friendly at first glance, but is hugely versatile - and the preset sounds are stunning as a place to start.

My initial impression is that the fingerboard isn't particularly effective as a midi controller for 3rd party VSTs. So you would buy this fingerboard for its synth engine and sound design capabilities, rather than as a MIDI controller for orchestral (etc) instruments.

It is WAY more expensive than similar fingerboards, so is definitely an investment.

Continuum is one of those instruments where you'll probably already have a good idea or what it is and why you want one if you're actually seriously considering one. A bit like if you were considering of getting, say, a professionally built hurdy-gurdy or a full Serge modular panel instead of an electric guitar or a synth keyboard.

If you're more a synthesist and need a lot of synthesis power, a flexible architecture and great sound in an easy to program package, do consider something like Waldorf Iridium. If you want the EaganMatrix modular engine and an expressive way to play it but are more a keyboard player, Expressive E's Osmose has a comparable amount of DSP power as Continuum, wonderful sounds, and a mind-blowing synth style keyboard that responds to even the slightest touch.

If you're eg. a violinist or a trombonist, an experimental composer / sound designer, or a microtonal musician, who feels it'd be bliss to have a super sensitive continuous unquantized playing surface, and a complex synthesis engine that responds in lightning speed, then there's really no other option. I hesitated even trying one for almost a decade - now that I did, I'm wondering why I didn't sell most of my instruments and buy one way earlier.