I see online it says 23.5 inch wide? What do they mean by width, does the actual seat you sit on 23.5 inch or is what including the arm rests and its' really narrower than that. I'm looking into ORD-LHR J class and BA lists 20 inch for club world and was wondering if UA really is wider, or if you include the arm rests, it's the same size at BA.

Has anyone experienced both carriers and came compare which is wider for sleeping.