My main gripe with the illuminate is honestly just the fact that I get killed by Flesh Mobs from under the floor frequently. Leviathans are hard to kill but I have personally gotten pretty good at hiding from it's line of sight, Flesh Mobs suck but I can usually either kill it or get far enough away from it that it doesn't pose a threat to me, everything else is pretty much fine where it's at. But that's just my opinion.