lets see if I can take a bite at this piece of cake
@ OP
1| the base flaw in all of these all-in-one coolers is the pump and chamber in which its housed in. Its weak and cramped into a tight space. Might want to check out your friends CLC and see how warm the chamber is, not a good thing for something with a lil heart.
2| the second flaw would be the use of and aluminium rad along with a copper base plate thas in contact with the cpu/heatsource. corrosion does happen. In fact coolant inside that all-in-one loop doesn't prevent corrosion.
you do the math, after warranty expires on these units, you won't have anything to say to the manufacturer when it'll leak.
3|
Some people use coolant in their loops as well. Otherwise, coolant would not be made.
coolants were made for specific reasons for specific climatic conditions. Everything in life has it compromises, that is trading in stocks can give you huge dividends but the risk involved is high. So high that people loose sleep trying to make those ends meet. Like wise, coolants add restriction to your loop.
If you're referring to the coolants made by watercooling manufacturers...then put plainly, its just another money making scheme. Whereas the
"distil+killcoil" route is similar and far cheaper. Tested, proven and recommended by so many watercoolers than ourselves.
4| as stated previously, all-in-one units have a segment in the market, just that,
that segment is full of uniformed buyers.