Been to the Sugar Factory a few times now. The feel is very underground, and quite cozy. When there is a dance party, you can dance on stage, which is cool.
The music system is pretty good, loud, but not ear popping.. I am not a technician, so I have no clue how they do that.. but it feels good when you cycle home the next morning at sunset... yay, I can hear the birds!
The drinks are not super expensive, just the normal price for Amsterdam night live. What's cool though is that when you order water, they always ask you if tap water is OK. And of course that is free. So that makes it a bit easier to stay hydrated :)
All in all a nice club, good vibe, nice people... just go there! :)