they are fine as long as you service them and replace the DPF filter when required, if you don't then expect big repair bills later on.
for what its worth the newer D2's have a better DPF system that doesn't require replacing the filters ever 72k, I think its from 2012 onwards.
Ignoring the dpf can result in some nasty bills, worst case, dpf, sensors, pipes, egr & turbo failure. for the sake of around £300 fitted just change the dpf on time and you should be fine
