im pretty sure they've got a virus, and i think apart from that they mostly use softsynths... dirk saw a photo of dj wag's studio, which has racks and racks of equipment and he just laughed and said "fcuking showroom..."
its so much more about what you do with the sounds than what sounds you have to start with. the uberdruck sound, like so many out there, is a processed, mangled, fudged up sound... its all about the processing (obviously a fat sound to start with helps...) like the timestretching/flanging on his vocals and his kick drum, which if you listen to it very carefully (or you sample it... not that i ever did of course :)) its the same kick that loads of people use (its on the technotrance essentials sample cd) but the left channel is slightly detuned from the right channel and the compression is beyond compare...