I know reliability wise Lexus is and always will be head and shoulders above most other cars but I wanted to share my experience of Lexus IS vs Audi S3 forgetting the obvious power difference.
Audi pros over the Lexus:
heavier doors instilling a solid safe feel, virtual cockpit is a master piece, more cabin storage space, more comfort for the front passenger as on the IS I find the cup holder gets in the way and there is no real comfortable armrest for the front passenger, door courtesy lights on the rear too, rear door pockets, nice rear seat storage nets, more powerful bang olfusen stereo than the mark Levinson, tyre pressure monitor tells you which tyre is low, better paddle shift gear change, nicer feeling and quality steering wheel, alloy refurbs possible and matchable whereas impossible on the Lexus, four way seat lumbar adjustment on both front seats and thigh extensions, rear power socket
Lexus pros over the Audi
superior ride, smoother gear change, better driving position, beautifully damped switch gear i.e. buttons for the radio, windows and heating etc, superior road holding and steering feel, quicker response in movement when gear is selected eg reverse from drive, silent power folding mirrors unlike the Audi, better rear camera, cool mouse system is a little different but works very well, easier to use horn and cruise control system, puddle lights under the mirrors, better quality wiper and indicator stalks, much better start stop system where it's controllable with how much brake pedal force you use, blind spot monitor on the mirrors far more effective, the fact the car is a little different!