Go the TD5, much more superior and refined engine. As many have said, get familiar with the electronics and you should not have any worries at all. A big advantage of the TD5 over the 300tdi is power, while they might not come out with much stock, you can chip them to get more. In terms of outback travel, overtaking is much safer in a chipped TD5 than a 300tdi. You don't have to get a massive run up to over take a truck, you just go for it because there's plenty of power and torque to work with.
Towing is also much better in a td5 than a 300tdi for the same reasons.
Go the td5, you won't be disappointed.
Cheers
Hendrik

