The thing is, you can put any media that you put in your AC into the media compartments of the Marineland filters. So that argument is moot.
Also, while your ceramic rings may have a bunch of bacteria in them, they're about 30 times less efficient than the bacteria in the bio wheels. The bio wheels are far more efficient than any underwater media because they're exposed to so much oxygen. More oxygen = more efficient.
*However,* where the biowheels become a liability is when you're trying to keep your CO2 levels up for plants. The biowheels off-gas CO2 very efficiently. So in that case, you'd be better off using an AC or better yet a canister.
Basically biowheel technology is based on what large scale sewage treatment plants use. The reason they're used in that setting is because they expose the nitrifying bacteria to the air and they are able to gobble up N2 compounds much more rapidly.
The flow issues some have had with Marineland filters, I have not experienced. Once my cartridges wear out, I'll replace them with some other media. There are endless possibilites there.
I personally think both ACs and Marineland filters are effective if maintained properly. It's just what you're used to and what you're trying to accomplish.