Uncapped modulation options and hybrid functions housed in simplicity. Some exotic interactions between components of its modular architecture too. The oscillators hybridise with other oscillators for AM/FM synthesis, with the phaser (spelled 'Phasor' in Fathom) for unison-like voice generation, and the wavetable oscillator offers a giant pool of possible timbres. Multi-stage envelopes with modifiers that impose gating of variable width and position adds another dimension to articulation. The delay unit is so good it can serve in the reverbs' stead.
For balance, drawbacks of note is its demand on CPU, due to its sample-accurate signal processing. Of course, the sonic potential is compensation. There's some room for improvement to its ergonomics too, but as development continues i have faith these will become more efficient.
Fathom is substantial despite appearances. A deceptively priced softsynth for the sound.
I have been using Fathom for only a few months now. I started on version 1.0.7. At this point it is up to 1.0.11. It has a bucket load of features but a few that really grab me are the extremely powerfull envelopes and the built in delay. You can not only draw your envelopes but can double, triple............ and so on giving you a sequencer type feel. The delay is a three headed monster giving you COMPLETE control over left, right and center. This synth is capable of just about everything out there with alot of stuff we havent seen. I can see this being used alot for evolving soundscapes and one finger rhythmic dances. At this point it has a firm direction, is stable and a pleasure to program. Looking forward to the finer details.