I use aspen for my dum because:
-it's easy to spot clean
-it's inexpensive
-it has very little dust
-ingestion danger is low
-more attractive and a lot less dirty than newspaper
-4 out of 5 dentists recommend it (okay, so maybe they don't know that much about dums)

You said you don't need a hide with aspen? Are your dums all juvies? You'd need a lot of aspen for an adult dum to hide in!