Sway bars are designed to transfer the weight or pressure if you will of your vehicle from the outside wheels in a turn for instance to the inside. It's real job as I understand it is to equal it out on both sides as best as possible in order to maximize traction of all 4 wheels w/o them you tend to loose traction on the inside wheels. If you think about it which tires start screaming in a turn the inside? or out? The inside because the weight is being transferred to the outboard wheels and as a result the inner wheels have little pressure on them.
Traction bars for my purpose help stop axle wrap because I have a lift with blocks in the rear. Their job is the keep the
[email protected]#$ end in contact with the ground, no wheel hopping, no axle wrapping etc...
Are they worth it I think they are both worth the money if your circumstances warrant it. A stock truck I doubt it but imo a modified truck yep definitely. My truck is modified and I will be getting traction bars and upgrading my front sway while adding a rear if it's available.
Those are my basic understandings of it.
P