Steering box upgrade

Has anyone installed one of the flaming river steering boxes into an older mustang? If so is it as great as the company claims? 500 bucks is a lot of money I'd like there to be a significant improvement in the steering if I'm going to spend that much. So, if anyone has tried it I'd like to know how it worked out.

Thanks Everyone.

The upgrade depends on whether its power or manual steering. I have power steering and having the new box on the bench there was no play, in the car the steering improved! But there is still a lot of play in the system because of the power steering, so i'm hopefully going to upgrade to rack and pinion. I hope this helps