My main goal for this new machine was for it to be as silent as possible and yet powerful enough to handle high-res (for now - 1080p, that's what monitor I have) gaming at max and all the work I do as designer. The result I got is exactly what I wanted. My new PC is very powerful and very silent.
I finished this build 6 months ago and since then been using this machine for at least 7 hours/a day. Had no problems whatsoever, everything is working perfectly. While using AI Tweaker tool from ASUS I managed to tune PC fans to turn on depending on temperature. Result: when idle my PC is running as silent (at least I can't measure lower) as my ambient noise is (app. 40 dB), while running only 2 fans (CPU cooler and one case fan). Though I'm pretty sure it is much quieter. What I'm really sure is that my external and internal HDD's make a lot of noise now...
My PC is sitting on the floor under my desk, so I didn't need glass side panels in my case, nor any RGB lighting or braided cables. So I chose (in my case) best case I could choose: be Quiet! Silent Base 800 mid tower. It is full of customization abilities and has a lot of sound-dampening material and is easy to cable-manage. Ant it looks really cool jus sitting there and making "no noise". Just like a sleeping powerful beast under my table :)
I have also tried some overclocking using ASUS provided options in BIOS. At 4.4 GHz I was having max temperatures (under load) of ~80 °C degrees with my CPU cooler. I assume that is totally not bad, bearing in mind that this CPU cooler is rather small. But this was just for testing. As my daily driver I'm running at stock speed of 4 GHz. That is enough for me right now.
Overall I am very happy with the parts I chose for this PC build and especially with results I got. Of course, there is no stopping: one can always buy an M.2 SSD, 1080 GPU, liquid cooling and etc. But for what I have right now I think it will be enough for me for at least several years (I'm not hard-core gamer). One thing for sure is that I really want a bigger screen with a higher resolution (instead of my current 24" 1080p LG).