I think it's mostly a looks thing. I considered one for my Rampage VI Extreme but I purchased a Supreme EVO Red about a year ago and I really liked the look of that so I used that instead.

The VRM situation isn't really concerning to me because I have 4 x 120mm fans right above the motherboard exhausting through a radiator. So there is a lot of airflow directly over the VRM.

As a result even with my motherboard under a 100% load across 10 cores at 4.5GHz (7900X, 1.125v) the VRM is not hitting more than 60c and I believe they're rated to over 100c. So I don't think for my board and my air situation that going with the monoblock was warranted for overclocking reasons.

However I know there are other boards with poorer VRM's and if you're trying for a very high overclock perhaps it's warranted.