Never, ever go to Turnmills. I heard a lot of great things about this venue but it is just crap.
As some people already wrote, the security personnel is very hostile and aggressive. After one hour waiting in the queue you had to wait an additional 15 minutes for the wardrobe. Inside it became even worse.
The main room at Turnmills is so chilly that you could be dancing in a fridge. Also, you are not allowed to dance everywhere. If you dance where they don't want you to dance, one of the 'friendly' staff members comes and steers you away.
So, compared to similar clubs like Fabric, Turnmills is absolutely not recommended.