Yup. Ditched poly/carbon type cartridges years ago. You can run a power filter with just about any combination of poly, pads, etc, with or without carbon, bio-media, etc. Anything with surface area that you put in a filter becomes bio after a while, including poly floss and carbon-- carbon as bio needs to be rinsed occasionally and will deteriorate over time, but it takes a long time.
Beneficial bacteria could care less how you label your media, they just do what they do, which is colonize any material they can attach to with available oxygen and nutrients. That doesn't mean some media aren't more efficient as bio than others, but you can run a filter with nothing but filter padding or poly floss and it will do both bio and mechanical, just rinse instead of replace and don't rinse in chlorinated water.
As mentioned above, any mechanical media clogs with time and needs rinsing out. To what extent just depends on what's ahead of it in the filter flow. You might think of sponges as primarily bio or primarily mechanical, but they do both, as will any mechanical media.
