Ethereal is advertised as an additive pad synth. While accurate, there's more to it than that - it can also do "general purpose synth" just fine. Some people compare it to Rhino ... that's not really accurate, but there are a few similarities. I find Ethereal easier to program because it's not as sophisticated.
Sound: I have been able to coax sweet flute sounds, Hammond-ish organs, hoovers, harsh jangly sounds, and nice evolving pads out of it. The presets, additive waveforms and filter choices give a lot of variety. It wouldn't be my first choice for dance/trance but it could be done.
Features: Several features make it stand out from the typical two- or three-oscillator synth: the additive waveform generator, the eight drawable envelopes, and the flexible routings. All controls can be tweaked in real time while you or your sequencer plays. Most knobs and sliders have MIDI CC's assigned, or use "MIDI learn" to fit your controller. There are chorus, phaser, reverb and delay effects.
The Patch evolver allows you to breed new patches from where you're currently at. It's more useful (to me) than a random patch generator.
Version 2.5 substantially reduced CPU usage in some cases and patches.
UI: The UI is large - bigger than Rhino, B-4, and the Linplug synths (this is a problem on low-res screens). Ethereal attempts to make all controls available all the time - unlike z3ta+ and Rhino(the envelopes, samples, and LFO's only show one at a time). Good chunks of the UI are dedicated to the envelopes, additive generator and effects. Version 2.4 added a patch browser, increasing the size of the UI by about 15% (it's to the right of what you see in the picture above). Other than the envelopes, it's pretty intuitive.
Presets: 160 presets cover a variety of sounds - pads (strings, bells, organs, rainfall), leads (piano, rez, brass sweep), bass, loops (using envelopes), and samples. This is a tweaker's synth, but there's a lot of variety/examples in the patches Jon provides. Some are very good, some are "good but not my type". You can use the evolver or a couple of mouse-swipes to create new sounds.
Manual: provided in HTML format. It is complete but not overwhelming or heavily detailed. You should RTFM and experiment to get the hang of the envelopes, it's not "four knobs to twiddle" (some examples might be nice). Some minor tweaks needed (ie dial default is now linear not circular).
Customer Support: 110% Jon has responded promptly to every inquiry, bug report or feature request - often within the hour. Jon's also visible in the instrument forum.
VFM: Excellent. I've gotten more use out of this $40 vsti than some I paid a lot more for. When I later bought Industry, he gave me Granite as if I'd bought the synth package, an unexpected kindness.
Stability: Ethereal's never crashed on me. I primarily use it in FLStudio, and also in Sonar with DirectIXer (use alternate screen sizing option).
