I use ebay for everything, so I'm not prone to trying things out on there. My fender eliminator is from ebay, flush mounts, intergrated tail light, gps mount, etc etc. Never had any issues on there. Now, those are just universal so idk how the fit will be, but they're worth a try. The only issue I see with those is they only have one bolt that mounts to the frame, which leaves you with the risk of that bending. Deff worth a try though.
They look similar to my Shoguns, but I think I paid $70.... that's not bad for QUALITY bike stuff. Went down a few weeks ago and those Shoguns were worth every cent I paid for them. Do you really want to test if those cheap bolts, brackets, and sliders will handle the punishment?
Hit at the proper angle, with enough inertial force, and torsion, you'll snap almost anything. Frame sliders won't prevent damage in a high side, but rather in a relatively slow speed low side. Where they're invaluable is that common low speed, tight turn drop.
T-Rex uses 12.9 grade steel bolts. It has the highest shear strength of common production bolts. You won't find much better. If You do... buy it.
I'm actually interested in this, too. I've had my eye on Shoguns as well as T-Rex's. I stumbled across these no-name ones about a week ago, and I'm just not sure whether or not to buy them. I understand that you get what you pay for, but is having the name on the package all I'm paying for? What exactly IS the difference in a cheap pair vs. a more expensive pair?