Personally,
- for a few bob more, i'd fancy a small performance advantage over an air cooler or a marginally wider one with a 360/420
- Can't help it, i'm tied into the RGB circus but minimally ignited. AIOs dont overshadow the dimm slots hence RGB memory kits remain fully visible / no memory clearance headaches for taller sticks.
- as Chloefile added
"Put the rad to the top of the case and you can get rid of the CPU's heat pretty damn easily"
- Unfortunately back to the aesthetics... gotto admit, some of these AIOs are appealing to the eyes. Can't say the same for ALF-2 but this ALF-3's got some of that premium looking swag. Speaking of "aesthetics" when it comes to air coolers i prefer a more industrial look with more bare-bone metal sticking out, not really feeling it with the dark rock elite
- A marginal/negligible bump in perf; rads can be set to a push-pull configuration. Had this done on my NZXT KRAKEN X62 with 4 arctic P14s... about 2-3c difference in temps whilst gaming (i know, no biggie) with a nicely reduced fan curve for almost-whisper-quiet performance.
- is it just me or do those AIO sleeved tubes add some busy highway character to the build?
I know nothing of significant value for an absolute requirement + the CONS: less durable, permeation, more moving parts (pump), second noise emitter (pump), etc... sucks... but it sucks more without it
So far my X62 from 2017 is still running great.