I've installed two sets ( 4 bars ) on my TT and I love them 1 set of two bars front left corners and the other set rear right corner . They cut the rocking on front and back and sideways by a good 90 % I would say. Its not like having a solid foundation but the wife is happy They are super easy to install.
I made some great stabilizers with 2x8 boards, eye bolts, and ratchet straps. Take about 80% of the shake and wiggle out of trailer. Also use x chocks on my tires. I will try and take pictures of my process and post them. I think I have 20 or 30 bucks in material cost.
Here are some pictures of how I did the stabilizers. I promise these work. I put 2 up front and 2 in back and ratchet them tight. Boards are about 40 degree angle and I used the top lip of the I-beam to place the boards in. Give these a try before you spend a couple hundred bucks! 2x8 boards and mine measured 32" long.