From all the different types of aspen I've tried, Zoo Med is hands down the best. It is finely shredded, soft and my snakes love burrowing in it. The downside is that it is also the most expensive of all the aspens. Nice thing though with aspen for me at least is i can usually go a couple months or more with my boas as like i said, its easy to spot poops and pisses and it sticks to the stuff so you can just scope out a nice clump and then F10SC the spot and spread the aspen thinner across it. I do that until there isn't enough aspen to spread , then i just throw it all out.