Finished installing everything this weekend.
Running the i9 9900K at 4.8GHz, 1.225v on LLC5 in the bios (hovers between 1.181v and 1.2v under load according to CPU-Z).
VCCIO and VCCSA at 1.2v.
Case cooling is :
Intake : 3 x 120mm front and 1 x 120mm bottom
Exhaust : 2 x ML120mm on the H105 top, 1 x ML120mm top left, 1xML120mm rear
This is what I got after 20 minutes running Cinebench 20 and Unigine Valley, 27C ambient
Used Valley to simulate the heat from the GPU in gaming, as my card vents in the case which influences temps).
RAM temps were about 50-55C, likely influenced by the hot GPU air too.
I ran the test for another 10 minutes with the front and top panels off and it was 2C cooler with about 50rpm less fan speed due to the QFan custom fan curve.
I'm satisfied with the results, although I'm sure they could be better.
Gaming temps yesterday with AC Odyssey with 1080p were lower though, high 50s low 60s - very similar to the 4.5GHz 4770k I was using, but will see what it's like in much longer gaming sessions when I get some time.
I am considering playing around with the cooling arrangement though.
The H105 has shorter pipes than other Corsair coolers, but it does appear that there is enough length for the rad in the front so it could be worth trying.
The GPU, VRM, RAM and SSD temps will go up though with the hotter air circulating in the case, so it's a tradeoff.
Should be easy enough to swop and test, will update when I try it.