corsair offers 5y warranty incl replacing parts that die if it goes bad,
e.g. you get the pc replaced if it explodes tmrw.
when you get anything else, you pay for it, so there would be no difference if custom or different aio.
yes, de-ionized water (type I) is the cleanest, and you want one drop of 5% biozide solution per liter of fluid.
i used it in a loop with a "dirty" (slimy residue/fishy smell) resorator to test it, just flushed solids out,
then filled with (only) distilled water and added the biozide.
after 1y nothing in the loop whatsoever, so with deionized water, its gonna be fine for a while.
I just realized that the cost (money/time) nowadays the decent aio dont get worse perf than a custom loop that cost more.
unless utter silence on pump is needed (which really isnt the case, there are just better solutions to decouple them from case, pump still making noise),
because they are separate (from the block), i dont see any difference between my eisbaer and a custom loop that (can) cost almost 3 times as much.
the arctic is a good unit if its just to use water/better than asetek design (high pump failures, very low flow),
but the additional money on something like the eisbaer is worth it if you want options for later (another rad/block/pump).
e.g:
the 2080 i have comes with an (asetek) cooler that is identical (block/pump) with those corsair and the like (CPU aio),
its not just loud, but annoying as hell (pump has high freq whine), especially since no other noise.
so ill swap the card for one with water block, add another 120 rad, and a D5 pump/res later.
since all are "reg" LC parts, i have the same option as on a custom loop, incl no need to tear down everything when expanding.
yes, they have less pressure, but they do that at less than half dba (and beats the NF P12 as cooler fan)
and i cant find any noctua/noiseblocker that can match an arctic below 12 dba.
i prefer to have less noisy fans running at almost full speed, less ramping up/down with cpu load shifting a lot,
and with gpu and cpu both under water, temps for each are about 30-50*C less (depending on load),
which means there is no need for high rpm/air flow in the first place.
but sure, going up if you can stand the louder fans is fine, but i can even do push&pull (2x fans)
for less than the other brands doing only one.
at least for me, with 6-8$/per arctic fan, i just dont see it making sense to spend 2-3 times for "10%" gains (for silent fans).
maybe look at the bionics, i like them as they are powerful but silent, and the blade material doesnt attract ANY dust.
ran two for about 1y, looked like new, when i had to dust others after 2 month).
im a silent "whore" and haven't used a seal/gasket in the past 5y on any fan below 20 dba.
proper cases usually dont need it (less resonating than those cheap flimsy cases).
edited for typo and adding info
