According to this
http://en.wikipedia.org/wiki/BMW_1_Series_(F20) the M135i has exactly the same torque as the 125d over twice the rev range
With the 8 speed AT on the m135i, the downshifts are so quick you're never in the wrong gear. Put your foot down at any revs in any gear and you're almost instantly shifted to the fat part of the torque curve. Push harder and it'll shift you to the fat part of the hp curve. Just make sure you're not too close to anything when you do so because it really does take off like a scalded cat