Here is my opinion on it:
I drove 30k miles with my 5100's and OME springs with OEM UCA and it was 100% fine at 2" of lift. I had Dirt King UCA on hand and finally installed them. They help you get more caster which makes it track straighter on long highway drives. Other than that I do not see any real difference in daily driving. They may gain you some strength if you rock crawl, but most of my offroading is deep mud or fast fire roads so I did not see much difference in durability.