I looked at a couple of 2.4Ds before buying my 1.9TD Westy. They’ve got a fair amount of low end grunt but do feel a bit ponderous through the gears. As pointed out above, they’re not as slow as you think and are a pretty comfortable cruise on the motorway.
The 1.9TD needs to be worked a bit harder but feels a but nippier through the gears (you need to tackle hills in a singlespeed style though 🙂 I personally preferred how the 1.9TD drove, but it’s all down to personal taste. I think both have pretty good reliability records.
Servicing is slightly more expensive on a 2.4 I think because it’s a 5 cylinder engine.
As stated above, both are pretty gutless compared to a TDI, but you pay more for them. For what you describe, I’m sure it will be fine provided it has a sound service history.
Have a look at the T4 forum – there are a few threads on there about the 2.4.