I would say that live rock is an extremely efficient method of filtration, when used in conjunction with a protein skimmer, which not only pulls junk out of the water, but also oxygenates the water. I used a canister filter in the past, but it contributed to nitrate problems... Unless you are prepared to spend a lot of time keeping them clean, I'd skip everything but a protein skimmer. However, I have seen a lot of amazing tanks that use canister, trickle, power, wet-dry filters, etc... So they do the job too. Just not as good as a protein skimmer, in my opinion.