Mine have been holding up great if anything I highly recommend swapping the plastic washers they come with for metal ones. It made a big difference on mine after I broke a washer running over a parking curb. DOH!
They curl up like a taco. Nothing a couple bricks and a heat gun can't fix. I have a full set of used flaps and most of the hardware I'd sell you cheap if you like.
They are crap. I lost one, yet all the screws stayed put. Weak material. Tore right through. Go with IKEA cutting boards. Much cheaper, but basically the same material. Seriously. Honestly, RallyArmor is a huge ripoff. You can buy screws and material for the flaps much cheaper than RA. Basics or Classics.
I would say depends what you use them for. For myself, it's just DD, not rally, mostly to keep the road construction and salt off my car. Works perfect for me. I've had mine for about 4 months now and not a drop of tar is on my car.