I'm quite sure some people here use Reaktor in their music.
Yes, it's out and revamped. And free update.
User interface has changed.
NI tried to make it look "Ableton-ized".
Still not decided is I like it or not, even if it looks quite neat.
They have added 2 new synthesis modules: additive and modal.
Now it includes Electronic Instruments 1 & 2, which is a pretty good deal if you ask me!
Some revisions to audio engine have been done.
Overall, I'm hoping it brings more sonic possibilities and easier navigation.
More details here:http://www.native-instruments.com/#/en/products/producer/reaktor-5/?page=1565