^^ on my 2013 535xi the hydraulic steering is definitely different between Sport and comfort modes. I was surprised since i thought this was only limited to the non Xi models with the electric steering but i am 100% sure it is different between modes. In comfort mode the steering is feather light and Sport mode feels more heavier when you are about mid way into a turn. I noticed this because although its heavier it still feels artificial compared to how my E90 335 felt.
2014 LCI 550i M Sport | 3D Design Front Spoiler | BMW Performance Black Kidney Grills | BMW Performance Trunk Spoiler | BMW Performance Gloss Black Diffuser | Painted Reflectors | Wincos 30% Tint | Supersprint Quad Exhaust | AC Schnitzer Springs | MORR VS8.2 Brushed Finished Wheels 20x10R and 20x9F | Michelin PSS Tires 245/35/20F 285/30/20R | M550d 16mm RSB |||More Photos of my car here|||