Snow,
Here I am the mommy. My daughter's the piggy mommy, but I take care of the cage cleaning and I buy most of the piggy stuff and the reasons we went with fleece are:
Cost
Cleanliness
Reuseablity.
Cost was the biggest issue.
Let's say you have a 2x4 cage. I piece of 2 yard fleece will cover your cage and half a queen size mattress pad. Here I can purchase a mattress pad for $27. It does two 2x4 cages. 2 yards of fleece is around $14 (before any sales)
So for $41 (before any sales-I always use coupons or sales) I can get a full bed of fleece. Changing it bi-weekly, I expect a piece of fleece to last me at least 6 months.
Now if I were using another form of bedding, I'd have to replace that same bedding each time I decided the cage needed changing. So for about the same cost (a large bag of carefresh is $20) I would have to pay out that much each time I changed the cage.
To me, the fleece stays cleaner. I can see the poops and vacuum them away. In the carefresh or other litter, the poops mixed with the litter and I had to change the entire cage in order to get it really clean looking.
Fleece does need to be washed, but it is reusable, unlike litters. If you have your own washer/drier that isn't that big a deal, an extra load or two a week. But if you don't, you'll want to figure that into the cost. But still, to me, the fleece is cheaper, the animals seem to me to stay healthier, it's reusable, it looks nicer, can be changed to match your decor and can be changed as much as needed if your animal does get sick with little extra cost.