Yup, ask the same question on the VW/Audi forums for some more biased opinions.
From my reading about the Audi TDIs it seems that 1.9 > 2.0 > 2.0 (125kW) in terms of reliability. There were two 1.9 versions offered on the Polo, though.
Keep in mind VAG's 120k km service is a biggie.
I wouldn't mind having an Audi :fencelook: