Best Buy just made my decision tougher

I was all set to get the 512 go steam deck oiled but Best Buy just put the rog ally z1 extreme for $499.

I love steam but hate buying an older system spec wise minus the oled but I can see where having windows on the ally wouldn't be as good.

For the price point of $499 for the ally and $549 for the deck, which is the better buy?