If you are a user of Spectrasonic Omnisphere 2, there is public beta testing going on for their new version 2.5. The new version includes support for using some popular modern synths as controllers for the Omnisphere SW synth. In the beta 02 version they have included a Prophet 12 profile, where the SW synth makes use of the specific P12 controls, like editing its 4 layers using the corresponding 4 P12 osc features, as well as adding some P12-ish presets, including some of the P12 oscillator waveforms.
As I often use the P12 as keyboard to my DAW setup, I have experimented with mapping up some P12 knobs as MIDI controllers to SW synth parameters - very tedious work.
To me, Omnisphere is the most powerful SW-synth and a personal favourite. The integration with P12 and most of its knobs as named front panel controller unleash really interesting real-time editing possibilities for Omnisphere. The final release of v2.5 is scheduled for the summer (free to registred 2.0 users) and I'll work hard with the beta to help ironing out the bugs I discover.