No Easy Answer I'm afraid. Really down to personal preference.
On 7.5 tonne I've sold everything from Daf to Isuzu. For many years as a business we favoured MAN TGL due to the reliability, however Daf are a good choice as they are lighter so offer additional payload and in my opinion have more robust cabs than Isuzu, Hino or Mitsubishi (not getting away from the huge payload on these though, however I would have thought overkill for most scaffolders). As one of the mass products here in the UK, DAF parts are easy to come by and service/repair agents are more widespread. It's a similar story with Iveco Eurocargo's, we sell in the region of 120 each year, we have customers that only buy Iveco and wouldn't consider Daf or MAN. In terms of servicing and maintenance costs, as a business that operate in the region of 800 trucks here in the UK on contract hire, we analyse costs asset by asset. Over the course of a year service costs are flat between DAF, Iveco and MAN. With Part costs it really depends on the part. What's cheap on one truck could be more expensive on another. Strangely there's no pattern, vehicles have common faults and apart from a truck that's been built on a Friday Afternoon you tend to spend a similar amount of money regardless of manufacturer. My advice? buy a product that your local service provider is a specialist in, saves time and money and keeps you on the road. If they are MAN, DAF or Iveco specialists with experience and trained mechanics it makes things so much easier.