I used to get around 800-900 out of a tank in the TD5, around 500 towing the van which in my opinion is very good. The electronics can do your head in but if you go the TD5 get one with service history and try to get as lower k's as you can. I've heard of people in TDI's getting well over 1000km out of a tank but they aren't quite as fast as the TD5. They really are a great vehicle in every aspect but if you get the wrong one (like my second one) they can be a money pit. Would I buy another? well yes I would but I would be more particular in choosing I think. If you do look at the TD5's although they are more expensive try and get the D2A which is I think 03 -04ish model. They had the factory centre diff lock. the 01 -02 didn't have it at all and the 99-01 had it but was not connected up in the cabin which meant if you wanted it you had to fit a later model transfer stick or make a cable to activate. With CDL they reckon they're almost unstoppable in conjuction with the traction control. I reckon take both for a drive if you can, obviously the TD5 will feel better as they have a bit more go etc. Although I now have a Toyota I am still a fan of these as they are a very nice vehicle to drive and probably a far better 4by to drive as far as comfort etc. I cant really recommend which one to get as they are both good vehicles and each has their advantages and disadvantages but get a good one and I reckon you'll be happy with it.
End of the day they are great value for money, you get a lot of 4WD for your dollars in my opinion.