I have owned a lot of humidifiers and think the Hunter Carefree is the best. The permawick lasts many years so the cost of changing a paper wick is aliminated ($40 per season based on $10 per wick). On the downside the onboard humidity sensor registers much higher when the unit is not running. This at times prevents the unit from starting again unless you manually start it by adjusting the humidity level much higher. I have very large rooms and a large house so I rarely have this problem. I still reccomend this humidifier.
This was a replacement for a 10 year old similar hunter humidifier. It does work. But it will not run 36 hours without refilling. We only use it at night. We run it for about 10 hours each night on the lowest fan setting and a high humidity setting (so it never turns off automatically). I have to refill it every third night or it would stop running sometime during the night. Other than that - I love the perm-wick filter - It can last all season. And I like the option of the different fan settings, the auto-turn off when empty, and the low water indicator. I'm not too crazy about the digital controls. When you turn off the machine they all reset to default so you have to reset it every time you turn it back on if you want it different than the default. I was happy with the older models manual knobs. But it does work and the pluses to me far outweigh the cons.
As far as fan noise - yes, you will hear this running in a quiet room. But we like the white noise.
I just got this one a week ago replacing my last one I had. The last one was in its 3rd season of use and when I went to turn the fan knob, I got a very large shock and it blew the unit. I called customer service which sent me a new one ASAP. This new one, 34407, is very loud. I also do not like the digital buttons. I prefer the dial knob. It works ok, but I have to turn it off at night as the fan is much to loud to sleep with on. (even on the lowest speed)
Used this last year and it worked great, pretty much kept our 1400 sq-ft house above 50% humidity. Started using it this season and it only worked for a day and a half. I hate buying things that only last this long. I cleaned the unit before storing away for the winter, tried cleaning it again after it stopped working to no avail. I guess I'll try a different brand.