I've been running it for 2 years. I have a 36" Irok on it now. It's silent, no rattles. I really love the bumper, but on the highway the tire kinda moves. The movement is sideways, back and forth, kinda like it's shivering. It's always concerned me. I'm guessing this movement could eventually stress the welds. I'm moving up to 41s and don't plan on keeping the tire carrier.
I might be wrong... But I think that is going to be standard on a carrier with only one pivot point. I have an XRC bumper/carrier and don't get any rattles, but looking out the back window the tire shimmies a bit while at speed. Nothing drastic. I think there is just slight movement against the latch bushing and maybe a little flex on the pivot point. I would say that its normal.
A carrier the the OR-Fab or Genright attaches at 4 points on the body so it probably wouldn't have any shimmy or shakes.
Anyways, I like the Synergy bumper and if they say it can handle a 42" tire, it probably can.
I am pretty sure the bumper/carrier is considered a hard part and covered under their lifetime warranty... if for some reason the carrier bent or broke off.
"All products, aside from wearable items and those otherwise noted, are guaranteed to have been manufactured from premium materials, free from defects and subject to Synergy Suspension's Limited-Lifetime Warranty"