It's the best, as Big Truck said, but it's also the most involved to build right!!! A Watt's Linkage takes up a lot of room, takes some careful designing to work them into a car but IMO well worth it. The bars should be parallel to the ground at ride height. Make sure you have a strong and well braced center pivot. I use heim ends on the rods, remember the rear end has to be able to move up and down and the resulting pinion angle change so heims are necessary to avoid having anything bind during the travel... Speedway sells a basic kit, not a bad deal with a bit of tweaking and bracing they work fine. I usually just build my own components in order to have the best bar placement and bracing...