On paper, the auto is the better of the two as there should be no heavy wear of the clutch on take-off, particularly when towing or shifting heavy loads. However, like all pick-ups, the automatic gearbox in the D-Max isn't great to drive, which means I would personally choose for the manual. I'd recommend test driving both versions to see which you prefer. If you don't mind the slow, sluggish characteristics of the auto then choose that as it will serve your needs without problem. For our full review of the Isuzu D-Max, see: vans.honestjohn.co.uk/van-reviews/isuzu/d-max-2012/