Hello! I haven’t ever had the pleasure of using a U5, but it seems like a competent piece of kit.
However, I did recently review the Arctis Pro and GameDAC bundle. And its DTS Headphone: X support is undeniably good.
If you bought the standalone $179 Arctis Pro, you wouldn’t need the U5, as it includes a small USB sound card, so there’s that to consider.
The Arctis Pro with GameDAC doesn’t support any other headphones, so its less upgradeable long-term.
So I guess then, you’d have to consider all these questions.
Do you need DTS Headphone: X 2.0? Then you’ll have to buy one of the Arctis models.
Do you need compatibility with a wide variety of headphones? Then the U5 is your only choice.
Do you want a hi-res audio chain from end-to-end? Then the GameDAC bundle is your only option, out of the choices you’ve selected.
Do you need Optical Audio support? Then, again, you’d need the GameDAC bundle.
I do think the Arctis Pro sounds a bit better than the 3…but the microphones are identical.
Considering all the questions for myself, I’d pick the Arctis with the GameDAC…but only because I need optical audio support and I like the DTS Headphone: X software. It’s easily the worst value-for-money choice on your list.