So I'm shifting things around already...
GPU CHANGE - NO MORE HYBRID I've decided to stick with an air cooler GPU. The Hybrid kept making an intermittent whirring sound, and the radiator would actually sometimes vibrate the chassis. Combined with my ability to actually test a 1080FTW card and realize that it's actually REALLY quiet, and more importantly, the noise it does make under load isn't as obtrusive as the sound made by the pump (especially factoring in low vibrations the pump made).
FAN CHANGE - GOODBYE NOCTUA iPPC I love Noctua, but their iPPC fans DEFINITELY have an audible clicking noise to them when running (and it's especially noticeable when you're running them at low RPMs like I am to keep the build silent).
This isn't an issue with my hardware (tested this on a couple of other PWM equipped motherboard and confirmed the settings were correct in BIOS, same issue), and this isn't an issue with a particular unit because they ALL do it, even the 140mm ones. The worst part is that this clicking is VERY audible, and I actually attributed it to the pump in the hybrid card initially. Its just a very ugly noise.
So I'm back on my quest to find the best components. For fans, I've narrowed my options down to either the Corsair ML series or the SilentWings BeQuiet 3. I could also go with beige Noctua fans (which sound MUCH better than the iPPC variants, even at matching RPMs), but at this point I'm frankly a bit pissed off at Noctua for their inability to provide their user base with a fan that isn't an eyesore. It's like it's not enough that everybody buys their products, they want their signature color scheme to market their product for them, and the black model they DO make and advertise is of lower acoustic quality. Seriously, they need to step it up.
This is the result of 2-3 months of research and testing to create a very quiet, very powerful, classy looking ITX build. My goal was a machine that didn't compromise performance for silence, or vice versa, and I think this is the magic combination. The U12S is excellent, and matched with the upgraded Noctua iPPC fans with white chromax vibration pads: the result is good looking, easy to install, performs excellently, and incredibly quiet (RPM set to 35% of max at idle, which I cannot hear).
I tested a few different AIO (Kraken X61 and X62, both intake and exhaust config, top and front mounted, using stock rad fans and a few other reputable fan combos), but the results were always the same: cools fine but with annoying fan or pump noise. Plus it's not even necessary, the CPU never got hot enough to warrant losing internal airflow and gaining the increased noise. And the whole RGB LED movement feels just so unnecessary and overdone nowadays, I ultimately settled on an air cooler. And few companies do air coolers like Noctua.
I am using the FTW 1080 Hybrid for now, (in fact I'm waiting for a replacement from Amazon due to a strange intermittent whirring noise from the pump that isn't normal for those Asetek units in my experience). That strange noise aside, I think it's a great compromise: while the idle isn't DEAD silent, it's pretty close, and most impressively, the load noise is INCREDIBLY quiet. I use the second Noctua iPPC fan attached to the fan extension card and set the fan curves manually in bios to ramp with the CPU temps. I've gotten it to be effectively SILENT under load, while hovering around 60 degrees GPU temp after extended Unigen Heaven testing (45 minutes and temp didn't budge after 15 minute mark, with Ultra settings, everything maxed). It's so strange to play something at Ultra settings, speakers turned low, and be able to hear myself think. :)
Still debating on swapping the RAM for GSkill Trident Z modules (black and white color scheme) but not sure about clearance with the heatsink fan and whether, frankly, it would be overkill , with the black/white look. I think it looks fantastic as is, so we'll see.
***EDIT (2-5-2017): I got in the black/white Trident Z, but wasn't a fan of the look surprisingly. Not only was one of the modules partially obscured by the fan which looked awkward, the white/black RAM looked overkill inside when placed between the white/black fan and the white/black cables/cable-bar combo. Returned them and decided to stick with the Corsair LPX.
Also, the HDD is mounted behind the SSD mounting area, which initially caused vibrations, but I used rubber o-rings to provide vibration damping, which worked perfectly. I don't hear the HDD anymore (used to subtly vibrate the entire case).
I seriously tried so many different combinations of hardware that I'm surprised everything came together so nicely. Even the size of the U12S is perfect, as it allows me to detach the radiator+fan combo of the hybrid GPU from the case without having to remove anything. Seriously, if that heat sink was even 3mm thicker it wouldn't fit.
Goals: - I would love to find out how to get Speedfan to recognize the radiator fan I attached to the Asus Fan Extension Card so I can map that fan speed to the GPU temp. If anybody knows how, would love to find out. (SOLVED, SEE BELOW)
Hope you enjoy. It's not nearly as blinged out as many other builds, but I think this combination has a nice balance to it, and even better the components took priority to give the desired performance/silence while still being aesthetically pleasing. Thanks!
***EDIT (2-5-2017): I've installed two 140mm Noctua A14 iPPC 2000RPM PWM fans in the front as intake. Paired them again with the Noctua Chromax White anti-vibration pads, and mounted them with the Noctua SAV2 Black Anti-Vibration mounts. Results are very good: they move more air with less noise and make the entire interior look a bit more cohesive. Additionally, I solved my SpeedFan issue: I decided to run the front intakes through the Asus Fan Extension card (since I just prefer to set a flat fan curve at 43% for these regardless of thermals), and am running the rear F12 radiator fan from the chassis header on the motherboard. So now I gain both fan speed ramp delays to avoid annoying fluctuating fan speeds, and I can see the fan in SpeedFan so I can create a curve off of GPU temps later on. All good!
I will post pics of the updated rig later.