I've been testing a few different Z Nukes for a few weeks now. I have 4 different colors, all 173-174. I have pale yellow (almost clear), light red, pink, and a Glo. I'm very impressed. It is without a doubt the best of the wide rimmed drivers for pure D. The best way I can think of to describe this disc is a faster Flash. It is VERY straight for a wide rimmed disc. For example, hole #1 @ Cliff Stephens is over 500' in the long position, but it is pretty tight. There is a road width walking path that plays the entire length of the hole on the left side and woods/ditch beyond that. There is a huge oak tree about 380' down the fairway that prevents long hyzers, and water on the right if you turn your disc over. So the perfect shot is one that goes on as straight of a helix as possible and fades as little as possible. Since discs got faster than the Wraith it seems like 90% of people end up throwing a wide rimmed disc on a shot that goes straight, fades onto the pavement, and skips into the shule. Anyway, the Z Nuke is the first fast disc I've used on this hole that is relatively easy to keep straight and on the fairway and still get 420'+ of D. I throw it with about 5-10 degrees of hyzer, it flips up and barely over in a very straight line, and then fades forward. Today I landed on the sidewalk at the very end of the fade and the disc was so spent that it stayed on the pavement.
All of my different Z Nukes fly pretty similarly. My red one is the flattest (though they all have nice domes) and is also the least stable, but it's not dramatically so (maybe -.25 less HSS). The Glo is just as flat as the red, but it is as stable as the others. The clearish yellow is the most stable, but again, not by much.
I still prefer a Boss for hyzers that must hold their angle, for winds in excess of 10-15mph, and in the wide open where I can take a full swing. Besides that the Z Nuke has taken over my max D slot.
I will also mention that the Z Nuke is one of the nicest discs for my FH that I've ever thrown. For some reason it comes out of my hand 100% clean and is very forgiving from a hyzer release. I get a long shot just about every time, but I don't throw anything but straight/hyzer lines with it. I can't trust it for a helix FH, but my FH just isn't that good.