I believe we have some data on the 16HD. I'll get that posted soon. Just so we're on the same wavelength, by Non-HD, I presume you're talking about the ones that have 4 white LEDs?
An easy way to tell would be to look at the LEDs when they're off. The whites of a non-HD form an imaginary rectangle that spans the outer edges of the cluster while the whites of an HD form a triangle.
The thing with matching lights is unless they were made directly after each other they will have visual differences even if they're the same model. Most lighting manufacturers have their employees visually inspect them independently from each other. The human eye, coupled with memory is not the best at comparing colors so you can have lights that have various shades of blue and green. Sometimes within the same fixture.
If you get LUX Engine, you'll notice we serialize every cluster. This number pairs with the second that the clusters were made and is also associated with a spectrometer test of the cluster. Even though the variances are minimal, when you order multiple clusters, we make every effort to match their output.