Seen it in action. does a great job. Major negative is that you really gotta plan your sump layout with the rollermat in mind right from the get go. its very hard to incorporate it into an existing setup like mine. No space :(
It does a good job replacing filter socks. I hate filter socks with a vengeance. They smell, they clog up, hard to clean, expensive, etc.
Another thing i don't like is that these are made with clear plastic. You'd think that for $500 they'd be acrylic or something. Plastic just makes them feel flimsy and cheap.
Have seen folks plumb it straight into the overflow, and also seen some rollers plumed via return pump manifold. Gotta say the one plumbed into the tanks' overflow was catching a lot more crud than the manifold method. Going that route one would have to deal with keeping the overflow's flow low as recommended. I guess one can use a DC return pump to keep return's flow to lower level.
But yes, next tank build will be incorporating a rollermat of some kind. Again, down with filter socks!
then