This is my experience with the difference between CVS sterile rolled cotton and organic cotton balls.. ymmv
The organic cotton is softer and fluffier, and has much longer fibers. Rolled cotton is matted like you said with small fibers, less soft, and full of dingleberries (technical term). Rolled cotton I roll into a tight wick and it works great. Organic cotton I don't roll, just kind of press into shape and thread it through, leaving it fluffy. For some reason rolled cotton can be rolled dense and wick well but with organic it doesn't wick well when rolled tight.
Organic cotton balls I find a little easier to work with; rolled cotton is a little more durable and tastes a little better for me. For all of that though, I'm talking very little preference.. they both are easy to work with (with practice) and offer great flavor. So far my preference is the sterile rolled.. it's what I mainly use, but they both work so well it's sometimes a matter of which is closer to reach for when making a wick lol.
Here's a pic.. the top is about how much sterile rolled cotton I pick off and below is what it looks like after I roll it to make it dense.
