While I wouldn't go so far as to call canister filters a nightmare, they do require regular maintenance but if you are into SW fishkeeping, you should be ready for more and better general maintenance, whether it's checking water parameters, water changes, topping off, cleaning, etc. I have a canister filter on my reef tank and it's great for keeping the water clear and removing debris after scraping the glass and also for running carbon when needed. I keep 6 paper cartridges on hand and clean so I always have a fresh one on ready to put in whenever the flow drops off.
I would recommend a protein skimmer for just about any SW tank; when you see the gunk that a good one removes from even a pristine looking tank, you will understand their usefulness!