DxO Optic Pro is not any easier to use. If you already own LR, my recommendation would be just stay with it. As you already discovered, DxO has different modules and claims to have better result for certain function(and I agree). However, I am not aware of any meaningful functions that can only be achieved using DxO but not LR. Your other question, by integrated, it is actually just a way to provide access from within LR to launch DxO.