We have a Super Stalker. It weighs around 1,550 lbs. It was OK with manual steering and street tires. But when we put on 10" wide slicks, it was quite a bit harder to steer. We use the car for Autocross on a pretty regular basis. The steering with slicks was a real handful on that type of course. We converted to power steering with an electric hydraulic pump from a 3rd gen. MR2 spyder and a Chevette power steering rack. It made a real difference, I can think about driving... not getting leverage to steer through the next turn. Even with the street tires, I have to say it is more enjoyable. I highly recommend it. Being an electric pump, moving the car around by hand with the engine off is a breeze.
http://img.photobucket.com/albums/v640/snookwheel/th_P1040916.jpg
Scott