I have low round alloy DP slip-ons and like the sound. Quieter than my cored originals and a bit lighter too. I preferred the brushed alloy look of the standard mufflers but polished has grown on me. I could convert them to high mount if I wanted - they only need different link pipes.
This is the old Accessories Catalogue 90 to FE 600/750/900 that I got off Ducati's website but it is no longer there. You can download it from here http://www.megaupload.com/?d=VU73QO3T
and it should give you an idea of what they look like. My set I bought off eBay and they listed the part number on this catalogue and came in the original box. There are no markings or stickers on them though so I was taking their word that they were actually DP. Was a bike shop selling them so they were jsut selling some old stock they had.