The 140 is a better engine that the 170. i was looking for a Golf GT TDI 170. But ended up with a Jetta Sport PD140 for £5750. The similar spec golf with a smaller boot was almost £10000!!!
No it's not. The 170 is a better engine, smoother and believe it or not, more reliable. 140s eat heads (they suffer from porous cylinder walls which means a new head is needed) and also have very weak turbos.
The 170s are much more reliable, there are injector related problems however these are all covered under a factory recall for free.