Basically it's similar to the 2.0T but only 160ps. It makes an A3 with one around £1200 cheaper than one with the 2.0T and it will be cheaper to insure. 160ps is more than enough for me - it's 20ps more than my current 2.0TDI. Whilst I like the 2.0TDI it is noisier than a petrol engine. I had 4 1.8T Sport A3s before my current diesel and loved them all, but when I bought my current one there was only the choice of the 2.0FSI, which was hopeless and the 2.0TDI which was much closer in performance to the 1.8T Sport hence my choice of the diesel.
I'm not sure yet whether I will go for another 2.0TDI-140 or the new 1.8TFSI-160.