I personally like aspen but if I had to choose between the 2 listed, I would use cypress mulch. I used Eco Earth for a year and that stuff is a freakin mess. Sticks to everything, gets dusty when dried, can mold despite people saying it cant. I've never used cypress mulch but I have heard people say they have gotten bags with wood mites in them. Some people will freeze the bags, spray them with PaM or bake them in the oven but like I said, I've never used the stuff. I stick with paper towels for QT and aspen for my their normal substrate.