Most are sheetmetal, metalcloak are 3/16" steel fully welded with a built in gusset that bolts to the bottom of the frame (and they don't charge extra for it or sell it separately).+1 for Teraflex. All of the different brackets from the different brands seem pretty much similar. Sheet metal brackets hanging down from the frame asking a rock to smack into them. Teraflex saw the weak point that the brackets can add so they created the reinforcement brackets to make them stronger.
Metalcloak brackets are the best imo…..For a JLU who make the best front geometry correction brackets? Strongest? 1 piece? Best engineered?
Another vote for Metalcloak. They are super stout, and they move the lower control arm inboard a half inch or so, which improves tire clearance with oversized tires to maintain your turning radius without needing such wide offset wheels.
I just changed from a 2 1/2" Metalcloak lift to a 4 1/2" Metalcloak lift and added the geometry correction brackets at the same time. I moved up from 37" to 40" tires at the same time and installed the 40s on a set of 17x9 wheels with -12 offset a few days before installing the taller lift. The 40s rubbed hard on the lower control arms at full steering lock, and I thought that I would have to adjust the steering stops to be able to use wheels with such a low negative offset. Most people run -25 to -38 offset for 40s. With the lift installed and the geometry correction brackets in place there is no tire rub at full steering lock. I couldn't see how this was possible, then after looking I noticed the control arms were moved inboard. Bonus!
I also noticed that square edged bumps on road are absorbed much better, with harshness completely eliminated. That is partly due to the flatter control arm angle with my 4 1/2" lift than I had with my 2 1/2" lift. Another bonus! The other part is that I think the current King 2.5" adjustable shocks are tuned better than my prior Fox 2.5" DSC shocks were. Despite both sets being tuned by Accutune, the Kings are significantly better.