I ran MC, non-arched, 6" flares for nearly 10 years on a previous LJ. While some here don't like them, I had zero issues with them and they provided decent coverage and protection. There were multiple times I hit trees hard enough, on the flares, to rattle my teeth. The only damage ever received was scuffed paint. I did remove them a couple times, which was very easy, but preferred the extra protection they offered.
On the current LJ, I went Genright and am hoping this was a good decision. The rear flares are removable, while the fronts aren't. We'll see how it goes. In either case, the one thing I'm not a huge fan of is how much of the wheel well gets opened up when you switch from factory flares. It bugs me, but I'll take the protection, which is important in the tight woods I typically wheel in.