I've never used it. Care to tell us why you think it's better than the others?
Well, it's free, it has a ton of options for synthesis, and it has a solid preset library. But the GUI is sprawling and poorly organized, all the envelopes are ADSR-only, the additive synthesis is limited to the oscillators (in other words, it's not even close to being as versatile as Harmor), and the latest beta is from 2010.
Basically, you get what you pay for.