I am back to my 4.4ghz daily use OC after 7 hours of trying every combination of settings under the sun, I guess either my budget Z170 Pro4s or my CPU just are not up to the task 

None the less, 4.5ghz stable is still not a bad result I just would have liked to see more under water. It looks like I will have to wait for another board/CPU combo to try for the elusive 5ghz OC that both my previous systems denied me 

And the before shot

Aside from the awesome new Corsair H105 AIO I have also added a Thermaltake Riing 140mm fan, my local store didn't have any Arctic 140s in stock and I like the more subtle not over bright ring LED effect that matches the logo on my GTX 960 G1 Gaming. I may not like the Christmas tree flashing LED effects but a subtle glow always makes me smile 

As you can see there was plenty of tubing to reach the front of the case, even if I were to have the radiator mounted against the case then fans onto the radiator. I chose this configuration because it will allow me to add a pair of 120mm fans at a later date without having to dismantle everything 

I have done a few stress tests at the same OC I was using on the Arctic Freezer 12 (modded aesthetically). I am running my i5 6600k @ 4.4ghz with a 1.3v vcore. Both configs were tested with an ambient temp of 24c and as you can see from the pics the only change is the H105, the new 140mm fan was used for both the air and water cooling tests.

Arctic Freezer 12:

Idle: 32c

Prime Load: 75c

Gaming Load: 44c

Corsair H105:

Idle: 16c

Prime Load: 51c

Gaming load: 28c

As you can see, the gaming load on the H105 is lower than the idle load on the Arctic Freezer 12  The other temps are so far below the air cooler I think they speak for themselves. Now to overclock some more and see how far I get. I topped out at 4.6ghz using my Thermaltake Frio OCK @ 1.35v and couldn't run prime without a thermal event (100c). Lets see what I can get out of the H105 

I couldn't let all the water cooling potential of the Define S go to waste now could I?

I will have 3 140mm fans on the front when my order comes in, while the airflow is hardly ideal it should be ample with 3 of them running at their full 1000rpm. They are very quiet and I do like that. Add to that that there is absolutely nothing impeding airflow in the define S and it should do the job well enough. I would go with Noctua fans but I just can't stand the brown color and my local stores only stock the brown.   

The Z170 Pro4s only uses 2 rows of mounting holes vs 3 on full sized ATX boards. There was a locator standoff included in the case (actually screwed into it) which could have been the thinking behind the missing standoff and screw. I removed it and replaced it with a regular standoff. 

I have got to say, the thumb tightener for the standoffs included with this case is fantastic. It has earned itself a spot in my toolkit.

I really couldn't think of a better case for my needs. I am not into all the excessive "bling" in my systems, some subtle lighting sure but the flashing, pulsing, color changing thing isn't for me. If I ever use RGB it will be set to the color scheme of my build and left at a constant low setting in that color.