Cured LR vs. NON Cured LR

It depends on how it was cured, and where the live rock came from. I've seen LR-both cured and uncured--that is covered with coralline. Eventaully, if your tank is conducive to algae, it will grow and cover all the rock.

With uncured liverock, the big things are: a) hitch hikers--various crabs, shrimps, (including mantis shrimp), as well as die-off of critters (sponges, algaes, small corals) can cause an ammonia spike. Cured live rock shouldn't cause this mini-cycle, and your odds of picking up a nasty hitch hiker is reduced, but not gauranteed.

I would just like to throw this in in defense of uncured, yes you don't have to worry about mantids and other hitchhikers, but you might not get as much variety of assorted organisms either. Sorry Orion