I run the Virgin Superhub installed 48 hours ago in standalone modem mode and have hooked up my existing Belkin N1 router. I did that because I could not get the Superhub to 'see' an internet bridge [for re-setting] nor an ethernet VOIP telephone adapter.. With the original Belkin N1 router not having been re-set, all the old settings were still present and there was no need to change the WPA key on my small office set up (about 9 units). At least it has been good for my blood pressure.... I'm getting 29Mb/s hardwired download, 18 MB/s through the Belkin wireless and about 2 Mb/s upload. I'm happy with that.
BTW the installation engineers were kind enough to warn me that the Superhub had 'router issues'.