passive cooling = fanless.
Low noise fans don't cool for crap for obvious reasons....they dont spin very fast and push low CFM.
Water cooling isn't hard to maintain....every 6 months you drain the system and refill it with water, thats maybe a 30 minute process....the initial setup isn't hard per se, but yeah it does of course take more time that simply putting in a heatsink or something like that.
Buuut if you're like me and get water cooling but put on 130CFM 120mm fans then it's not so quiet anymore
But it's a helluva lot quieter than when I had my case with like 14 fans not to mention much cooler as well.