I dunno, the main UI, but not all the settings and popup menus, those are exclusive to Steam OS. And I know what Windows does, I have it on my PC. I have PCs everywhere, laptops, at work, and so forth, and there's always updates. Windows forces you to restart for their updates every month, and sometimes they just do it without even asking.
The VRR is nice, I am curious how the OLED 90 vs 120 LCD will feel, I think the bump to 90 on OLED will be very welcome in closing that smoothness gap between the devices.
But the colors on the OLED are simply going to outshine the Ally every single time. I am not even sure if I will bother buying Switch 2 anymore if they are really launching without OLED, I'll just sit it out and wait for the refresh this time around.
The Deck also is actually a gaming device, which is a big PLUS imo. Windows is not, though by default it is where everyone goes to play games, there is nothing saying Windows will make updates that don't negatively effect games in the future, while the Deck is gaming first, and only really. And the speed at which the Deck is evolving is very impressive, while Windows does very little update to update.