I really like Wraith SQR (the bigger version, with the sequencer). I've had Reaktor for several months, downloaded a Lot of ensembles for it, and built a couple myself. I think Wraith sounds better than most Reaktor ensembles. I don't know why, and I'm not sophisticated enough to comment on how exactly, but to me the sound seems richer, with more depth and brilliance and vividness. It has almost a tactile quality.
I'm really interested in virtual modular synths, and I've noticed what a wide variety of interfaces they have. Some are very complicated, some are overly simple, some are hard to figure out. Some have modulation grids that are a total mystery to me. For me Wraith occupies a sweet spot - enough detail that I can do a lot, enough simplicity that I always feel like I know what I'm doing. There are some Reaktor modular ensembles where I never feel like I know what I'm doing, and most of the time I can't even get a sound to come out of the thing. But with Wraith I can understand the signal path and do what I want to do.
ET has really thought through what connections to make hard wired and what connections to leave up to the user. Other people's mileage might vary, but for me, this is a great VST to explore modular virtual analog synthesis with.
And finally, the 22 skins and the large detailed slightly translucent knobs are really really satisfying. If I had a RL version of Wraith, I'd love it, it would probably cost about $5,000, but it wouldn't be able to do polyphony or unison. I'm happy with Wraith. The price seems quite reasonable to me.
I am not affiliated with ET and do not work for them. I just admire what's been achieved here. ET's other modules have been wild explorations into realms I haven't always even really understood, and I've admired them even when I've felt baffled by them. But Wraith is in many ways the virtual synth I've wanted for a long long time.