So the Noxon DAB USB stick indeed showed up as a christmas present. I directly tried it in Zuid-Limburg the southern part of the country where I found several countries' DAB ensembles before. No such luck with the Noxon DAB USB stick and its own antenna. Searching for other experiences in English or Dutch found nothing, but searching in German for noxon dab usb kein empfang found DAB+ USB Stick Terratec Noxon which has several mentions of the accompanying antenna not being great for VHF band III and being susceptible to interference from the computer. I also had the Pure One Mini receiver with me which found most expected ensembles without a problem. The Deutschlandradio ensemble was missing this time. Back at home I saw the same problem: on the top floor of the house where the Pure One Mini finds both the Publieke Omroep ensemble on 12C and MTVNL on 11A the Noxon DAB USB stick in default configuration finds nothing. Switching to the antenna I built myself for DVB-T scanning or to the Funke DSC310 antenna does give me both ensembles in the scan with good reception for 12C and good/average reception for 11A. One tip in the above forum was to move the antenna away from the computer. I tried this with a long USB-cable and that helped a bit: the Publieke Omroep ensemble showed up. So the accompanying antenna is bad, or the input sensitivity of the receiver in the stick isn't that great, or both. Which doesn't make it a great stick for trying to discover distant DAB ensembles just making it through. Or for bringing it along on trips.
Update 2011-12-29: Today I had the Pure One Mini playing a DAB station and booted the laptop and the reception completely stopped for a few seconds and returned with a drop in quality. Solution: move the radio away from the laptop. So VHF band III reception is quite susceptible to interference from computers.