I get that windows sucks, but having used both the screen on the ROG is just sooooo much better. Text looks much more crisp and I do have the option to run some other launchers and games I couldn't on the deck. Also the download speeds are way faster for some reason.
Fun fact, there's an advanced dev option on the steam deck to not power limit the WiFi card and it downloads 5-10x faster if you disable the power savings in my experience
IMO no, only because I do really like the option to run more than just the steam launcher. Like the battle net or Epic launcher. Also when I play some games like Dinkum I like to turn infinite energy on to make the game more chill and I can't run WeMod on the deck.
I haven't tried the ROG unit, but I can say the LCD and OLED Steam Deck displays are like night and day. It's a significant upgrade, and I'd be interested to see how the ROG display compares with the current Steam Deck.