This is absolutely the best sounding vst synth I've ever owned.
I own Komplete 12 (Reaktor, Massive and X, Absynth 5, Form, etc...), Synthmaster 2.9 and One, Vital, Thorn, Diva, and less popular synth vstis.
I reach for Dune 3 first because to my ear, the results are just incredibly inspiring. Watch a few youtube videos by Kevin Schroeder to get an idea of this beast.
Read the manual and check out Venus Theory's Dune 3 videos and you'll be designing gorgeous pads and leads in no time.
The onboard FX are premium, better than many specialized vst FX plugins. There are 1000 presets and they're fantastic.
The filters are widely regarded as the best available and sound amazing to me.
The only drawbacks are:
1. The preset browsing is outdated. I just save a copy of my favorites presets in my own folder.
2. Can be heavy on CPU with extremely complex patches. Worth it!
If I could only own one synth it would be Dune 3 because it sounds beautiful with very little effort, and can be made to sound otherworldly once you start to understand how to design sounds with it.