Impeccable
As this was my very first custom watercooling circuit, I was a bit afraid of having leaks, or difficulties to connect the different components of the loop together. Besides, to simplify my life, I opted for flexible hose (from Corsair, 10/13 mm), much easier to work with than rigid, hence the need to use compression fittings. Anyway, when it came time to assemble my system, especially the cooling system, I was pleasantly surprised to see how easy it was to connect the hose to these nipples, and I think they would have been perfectly tight even before putting the clamp on. I didn't have any leaks anywhere on my system, and that was on the first try. What a joy :)