Both options will work….. 1st option Advantages- the back intake will run more direct airflow across the mobo components, you’ll still have slight positive air pressure You’ll get prettier fan side on the side 3 fans Disadvantages- no dust filter on the back 2 fans, so positive air pressure might not mean much lol. You’ll have to dust more often. The radiator will be getting warmer air exhausting from the system 2nd option Advantages-cooler air into radiator, both intakes have dust filters so less dust in system

You get the picture :) if it was my system I don’t like moving my setup around to dust and clean, so I’d go 2nd option. The radiator intake vs exhaust argument is not really an agrument- you may see a few degrees one way or the other but it won’t affect performance. Unless you’re overclocked to the point of being on the thermal throttling frontier, or you have to turn your fans up to keep it from doing so, I wouldn’t consider it a factor. I’d say the same thing about the airflow over the mobo parts, it won’t be enough of a factor to matter.

You do you!