Now THERE is a tough question!
I feel like the Arctis Pro + GameDAC was designed to directly compete with the Astros. And they’re both well above what I’d consider the “good” line.
If you need something that works directly with Xbox One, you have to go with the Astro A40 Xbox One model. They paid the licensing fee to Microsoft to interface with the console and Steelseries didn’t.
And if you’re a price conscious shopper, the A40 sets tend to go on sale more often.
Beyond that it’s really down to which one has features that appeal to you more.
The Astros have a slightly lighter fit/feel, thanks to their softer fabric ear cups and the semi-open design. But the Steelseries model has a more “audiophile” sound signature, better isolation without buying an extra kit, and hi-res support.
With that hi-res certification and the newer DTS Headphone X 2.0 surround, you’re getting more features with the GameDAC, technically.
It’s really a wash as far as any “objective” standards go.
I personally think they’re both comfy, I think they both have a solid mic, and I don’t outright loathe anything about either one. If you forced me to pick, I personally enjoy the Steelseries model slightly more, but I don’t know what your personal preferences are. And I wouldn’t begrudge you just picking the one you could find for cheaper!