I hope this isn't a real question! :mmm: Just kidding. Performance wise, the scirocco can never beat it on performance (unless some SERIOUS modding is done).
Ride comfort is a contentious issue... If the ride is soft, it will let you down when you want to do some serious cornering. If the ride is hard, you will struggle on bad roads. You can have good cornering or good ride comfort. Never both. Unless you go for something like the adaptive suspension (not sure if the scirocco has this - BMW doesn't on the 135i to the best of my knowledge). Even then, you won't get the same characteristics at the same time.
The 135i is an amazing performance drivers car. It's like engaging hyper space drive when you hit the accelerator.
As far as interior and looks, the BMW is awesome. The VW is a nice change from the well established shape of the Golf.
This may sound a bit one sided, and probably is... But depending on what you want the car for and your daily commute will decide for you.
If you only had the 2 to choose between, the choice is simple. If you drive in hectic traffic for long distances (at low speeds) and don't do much weekend driving and don't want to - the dsg vw is for you. However, if you don't do much traffic driving and love driving good roads on weekends, you'll never look back after choosing the BMW. This is because of the hard ride, and the EXTREMELY heavy clutch. (assuming you go for the manual).
And as mentioned previously, RWD is awesome!