Well apart from different opinions on looks, it's also to do with performance too. The 12mm push fit shown would end up with an 8mm ID once the correct tube were fitted, (2mm wall). The next size up 16mm requires tube with 2.5mm wall so you would still have only a 11mm ID and a 16mm fitting is enormous. They also don't make the tube transparent in 16mm, I'd looked into this in the past to unify the system to all push fits but decided they were only any use in the smaller sizes.
With the 5/8" barb, (that is reamed out to 13mm ID), and correct tube I will have better overall flow possibility on the input, and it seems to be the accepted rule that more flow = better performance as far as a waterblock is concerned.
Must stop posting images in every reply or Joe will lynch me
, but spent an hour in the workshop and made a alu replacement for the blue plastic top. This one works (is not a fake), just got to do it another three times. seems to work just fine in alu, (just needs final polishing), so I may make one more and get a batch made by a local machine shop so I can convert all of my blocks.
