Air 14.7C?

You have your window open for some benchies?
So you're at 10C delta CPU to water and the Innovatek was 9.4C. Too close to call and within the margin of error for your instrumentation.
How long were you running Prime before taking those readings? And is that water temp before or after the block?
On the helix - keep the coils about 0,5 to 1cm apart. You might also want to make it spiral progressively inward (start at tube diameter and gradually decrease to about a 1,5mm diameter. Then put a final full spiral the diameter of the fitting to hold it in place).
Side note, nice CPU/FSB

What mem timings that at?