I wouldn't say they're that offset, depends how tall you are. Certainly didn't bother me, but I know Deako had trouble with his. Also doesn't matter if you get a Step-Auto or a later 7speed DCT car.
You're never going to get an unbiased opinion on a VAG forum, so whatever I put will be shot down in flames. However.....
The 135i is a better driver's car. I don't think you'll find a single Motoring press review of the car that doesn't score it very highly. Clarkson said at the time it was the best BMW since the E30 M3, 5th Gear had it up against a Cayman and it beat it.
The R is a good car, I'm not going to pretend it isn't. It's more practical, probably quicker point to point in the wet and will do 0-60 faster once mapped. It's handlng and brakes are a weak point, but throwing money at them can get you somewhere decent enough. I can see why people like them.
The 135i with non-runflats and a geo tweak has so much mechanical grip, it'll run rings around the R in the dry. It's capable of much higher power (500hp in N54, 400hp in N55) with nothing more than a map/DP/intake. It's just a beautifully balanced and enjoyable car. Big Brembos out of the box, glorious 6 pot noise and fast enough to make your eyes water.
As with everything, you need to get a good long drive in both and see which suits you best.