I see some points on the barbs and I agree with them, but personally I prefer the compression fittings myself.
Some might value function exclusively, but I love looking into my case and saying "whoa". Looking at pics of some of these amazing watercooled systems and how cool the compression fittings and tubing looked is what made me investigate watercooling to begin with.
The only problem I ever had with the compression fittings was on my swiftech max NB block. The little swiftec logo
interfered with the seating of the fitting and I had a small weep there until I caught it. I pulled it off and it makes a nice case badge now.

I just think they look a lot more professional on a beautiful piece like the collance 350 waterblock.
Just my take.