usine is a modular host , created first for live situation but it's so flexible yet It can be use for anything. It's not an host like cubase, reaper etc, so if you just want to record audio , there is a lot of host who can do this job. I actually thinking there is no limit to usine, and ( that's very important for me) it's very easy to use, whereas usine can be very complicated.
I'm not a sound designer and I don't search the most complicated sound of the world , i'm just a musicien who want to use incoming midi or audio and play with these, like I play with my instruments. I do not want to be locked up by a system of pattern ( like ableton live , a very nice software for live looping and electro music) but sometimes I need this system and usine is able to do this. Olivier Sens is the developper of this beauty and i think first a musician . you feel that when you work with usine.
Usine is unique so please try it , there is a free version !

gui:

near perfect. very clear, and very easy to use in live situation. you can do a midi learn or key learn on every control with a right clic.a lot of possibilities: grid ( like ableton live) sequencer and live (mix of both)

sound:
you can do what you want so in my opinion that's perfect.

doc:
very good . the manual is exellent, and there is a lot of tutorials

preset:
patchs and a lot of addon are present with a huge variety of sound ( from loop tools to crasy fx. If you buy it, you can access to a lot of another addon's.

support:
olivier is fantastic and the support is perfect.there is a new version each month !

value for money
forfree or 50 euros that's the best vfm I know in the market.

stabilty :

I never have a problem actually.

Usine is actually the most fantastic audio and midi soft I know.nothing more.