Here’s a pretty simple video clip from French publication Motorsport Magazine comparing the Audi S3 and the Subaru WRX STi. It’s an acceleration run from 0–250km/h and it would seem that S tronic gives the S3 the edge. Although, they’re pretty slick gearchanges in the STi.
S3 Sportback: 221kW/380Nm, 6-speed S tronic, quattro all-wheel drive, 1445kg
WRX STi: 221kW/407Nm, 6-speed manual, symmetrical all-wheel drive, 1525kg
[Thanks to Tim for the tip]