One thing to keep in mind is that a home file server with 15 drives is generally nothing like a file server of the same capacity in most other environments. I have a similar server and 99.9% of the time (probably an underestimate) all but one or two drives are spun down. So drive noise is minimal, and power and cooling needs are much less that they'd be if this were a file server in an office or a data center.
Of course that depends on the drives being used, mounting system, proximity to one another, location of the system and its ability to be cooled efficiently. I also have a file-server at home, and power draw and noise are minimal. But it's also in my basement storage room, so if it were loud, it wouldn't matter.
But when you do have to start up that machine, those drives are going to start up all at once and it'll draw some power...
But my comment was more about the noise of the 5x3 adapters, rather than the drives themselves. They usually don't cool very well even if you use the included fans, and rarely do it quietly. But again, it's all relative to the environment.