I had this for awhile and only tweaked the presets (particularly liking the multis). I liked the sounds, but I didn't explore sound design.
Finally, I took a few hours and mapped all the controls to my NI keyboard, and this changed everything for me. This is a beast. What you can do yourself is infinitely better than the stuff they give you. And that's just with one patch, and you can layer four, each with different arps and effects.
The MIDI learn capability is pretty extensive. Not only can you map nearly all of the controls (and each synth has the same ones, which makes it easy), you can also turn on and off the arp--and change arp modes, rates, octaves, etc. There is even a place in settings where you can set up cc control of patch changes, selection, and choice of A, B,C, or D synth. You can control all the effects. One thing that many Syntronik users don't explore is that it comes with 38 effects, derived from T-Racks and Amplitube, arranged lunchbox style.
The only limitation with my MIDI control is that I have already mapped out 8x8 pages of knobs, and plan to do more. I would need to do at least 4 times that to make use of the four synths you can layer in Syntronik. (Each of the four is mapped with unique MIDI ccs.) I sure hope that IK adds NKS someday.
If you do map Syntonik to your controller, be aware that that the MIDI mapping is only saved in a Multi, not a specific patch. I learned that the hard way.
@PerryD Since I bought it they have offered extra presets and samples for J-60, Pro-V, SAM, and T-03. Make sure you download these additional files if they're available. I think they only stay up for a limited time. I like the way that IK continues to support and improve Syntronik. The Deluxe upgrade is over-priced, but I'll probably get it when it goes on half price sale.