If a car is maintained properly the DPF shouldn't give you problems.
I disagree.... Short journeys clog them up, and even the best maintained car will have issues if you do a lot of cold starts and short runs.
Cars run rich when cold which produces more soot which clogs the filters. On BMWs they regenerate themselves, but certain criteria need to be met - water needs to be up to full operating temp, exhaust needs to be up to temp, and you need to be doing xxxrpm at xxxmph for the ECU to initiate a regeneration. This involves (on BMWs) adjusting the diesel timing the generate more heat in the exhaust and thus burning off the soot - if you never get the car hot on a good run, then they dont regenerate and they clog.
If you find a reputable remapper, you should have no problems. With a DPF delete / gutted, the software just needs to be modified to remove / alter the pressure sensors so they always show the DPF as clear and doing its job.
I had the 530d for 3 years with a DPF delete and Ive had the 335d for just over a year with the DPF deleted and never had a problem. Not only do you get the extra performance, but you also get more mpg