Well that AWD goes to explain some of the £5100 extra the BiTurbo Passat costs. Assuming £1500 (isn't that about how much Audi charges to go Quattro?) for the Haldex, £3600 is still a lot to be asking for 56PS extra on a GTD-R. If it can put all that power down, you're probably talking about a 0-62 time of around 6.3 seconds (faster than a GTI PP, but not by much due to the 90Kg ish weight disadvantage.
Distinguishing between quattro and haldex is not that simple... Audi uses the terms quattro to mean booth the permanent 4WD system and their implementation of the Haldex system. They can be distinguished by the alignment of the engine... all longitudinally installed = traditional quattro whereas the transverse installations are all Haldex...
Why is there such an interest in 0-60 or 0-62 times on this site?
It is a very poor measure of performance... unless, of course, you treat every time you stop at a set of lights as a drag race. If that's the case (possibly with the exception of the R) you have the wrong car... you should have gone rear or 4 wheel drive... a 1978 3.0 Porsche 911 SC with 180bhp would give a Golf GTI a tough battle 0-60...