Whats the main differance in the drive systems and is the new deisel powerfull enough ?

I looked at the new 4x4 before realising that the diesel is very low powered even if you could get it tuned. As for the 150 FSI engine it feels flat as a fart in my sisters A3 so I can't imagine it would be any better in heavier body with transmission losses. For me it's a non starter- were it on offer with the 2.0 diesel that would be another matter.

Dream Octavia MK2 4x4 would be the 2.0 FSI turbo but it's never going to happen.

As for the Haldex I believe it's a more advanced unit than the old 4x4 and has less of a space penalty as well as being better. Read on here that the aftermarket Haldex controller/chip for the old 4x4 does much the same thing.

New 4x4 has the latest generation haldex which has PreX, this anticipates slip rather than wait for it to happen and can also activate the rear wheels from standstill.

Dream Octavia MK2 4x4 would be the 2.0 FSI turbo but it's never going to happen.

there was a rumour in the press a few weeks ago that it will at the end of the year but to date I havent been able to get it confirmed anywhere

I doubt it will happen as it will be threat to VW/Audi sales.

Is it not the same as the new golf and engaged all the time ? my ideal car would be 4x4 hatchback diesel for when I go offroad into say a wet muddy field towing our caravan and be able to drive it mon-fri into work without poor fuel economy ! Or do I go for the KIA proper 4x4 offroader and pay a higher running cost ?

As far as I know no Haldex system used by VAG is engaged al the time. Would be a waste of fuel etc.