Jacking Rails

I never see anyone mentioning jacking rails and there are no threads that really have a lot of info about them.
I was just wanting to know if anyone had any comments on them or any experiences. I just ordered the Kenny Brown rails today and I'm hoping they will make it easier or at least more convenient when I have to raise the car.

I'm installing MM SFC's at the same time. I've had the subframe connectors for about 6 months just sitting in my garage. I just never have time to install things anymore, so I'm going to try to kill two birds with one stone.