I should add to my summary: though I saw some reviews suggesting the W may not allow kids, I did then see a few other reviews talking about people bringing kids. So I guess that's not a distinguishing point between the two properties, though the W may be less kid-friendly.

And the food prices upon further review are also less conclusive. The St Regis does seem to have lower food prices in many categories, though it's hard to know how comparable anything is. The W sent me the menu for Kitchen restaurant with prices, with the pages attached below. There are also links to some St. Regis menus on that thread. Overall prices appear to be pretty similar between Kitchen at the W and Orientale at the St Regis, but I don't know if those are necessarily comparable quality levels and portion sizes.