You set up ping relationships, weird as that sounds what it means is you get a percussive kind of synth that can get impressively complex. Good for dnb but begging to be used in experimental tracks, OnePingOnly has a different kind of learning curve although once used to it has high fun factor.
Pros: unique sounding, unique means of developing percussive sounds Cons: no GUI, supposed to be coming soon :)
It's a hard call, some people I've suggested get this free VSTi simply hated it. I played it in the context of a song the same people liked it.
Maybe I'm a easy touch but when creative ideas are made free for me to have fun with I'm greatly appreciative. Cool idea, thinking differently will get you used to the OnePingOnly world.