The Samuel 17 fits without a problem, and seems to provide good cooling performance. I paired it with a Noiseblocker NB-eLoop B12-2 fan. The overall rig is fairly quiet, but haven't dug into Asus fan expert in any detail yet to lower the noise level even further. My only issue so far is that the Asus software doesn't seem to be able to run the Noiseblocker at anything but full speed, but has determined that the 2 case fans can be controlled. Have to figure out why this is happening as I didn't think PWM fans were required (the case fans aren't PWM).
In most Asus motherboards there is only 1 true PWM header (CPU_FAN), the rest are 3pin voltage controlled headers (CHA_FAN 1, 2, 3), in some asus motherboards you have CPU_OPT, this is just a Y splitter sensor from the CPU_FAN, so in essence is a mirror header, so it will control the same way you chose the CPU_FAN.
Now the problem you are having with the Noiseblocker NB-eLoop B12-2, is that is a 3pin fan and you are using it on a PWM fan header (CPU_FAN), so as most motherboards on their true PWM header always send 12V and the mobo/fan regulates its speed via the PWM signal, in your case is like running at 12V fully because the motherboard doesnt know (yet) that you are using a 3pin fan. But asus was smart enough to cover this issue, and its pretty simple, you need to enter your bios --> Monitor --> Fan Speed Control, in there you will see CPU Q-Fan Control, you need to change it from AUTO to ADVANCED, what this change will do is simple, just tell the motherboard to not control the CPU_FAN via PWM control but via voltage regulation, aka how a 3pin should be. I'll leave a pic of my bios so you get an idea,
Once you change it fanXpert2 should be able to control it and tune it to your liking as your other fans. Remember to re run the tuning so it gathers the info from the Noiseblocker eLoop B12-2, else it will control it the same way it was before you made the change on the bios.