I have a piece of each – 2.5 oz/yd2 Apex and 3 oz/yd2 One.
Curiously, the actual weight was 2.62 for Apex and 2.38 for One. I think this is just that the actual weight can vary from sample to sample.
Measured loft was 0.68 inch for Apex and 0.60 inch for One – so almost proportional to the actual weight.
I measured Clo/oz/yd2 at 0.81 for Apex and 0.91 for One – although this is a tricky measurement. The specs I found are 0.82 and 0.92, which is close to my measurement but different than yours? Regardless, I think that the One is a little better. Also, the Clo/inch is better for One. Just looking at the insulation, the One has finer fibers which must be why it has better clo/oz/yd2.
Downside – the One is much more fragile – tends to come apart more – again, why it has better clo/oz/yd2? So, Apex you only have to quilt around the perimeter, but One you have to quilt every 3 or 6 inches. Where you quilt it, the insulation is compressed so you lose some of the clo/oz/yd2 advantage. And all the extra quilting is a pain to do.
I've done a couple projects since I had that data and used Apex.