Interesting review IMO, with colour accuracy comparison and benchmarks of DeckHD vs. original screen (and other “known good” screens).
I would be more tempted by an OLED screen upgrade, but colour accuracy looks pretty good tbh. Pricing is in line with an official (matte) screen replacement from ifixit - $99 USD.
I have both and I prefer the steam deck. The Ally runs games better when they run, but the trip there always sucks, to the point that you never want to pick it up.
The Ally is actually much more of a “linux-like” experience because you can get more out of it, but you have to put a lot more work into it to get there. The steam deck is like a console.