I like it! Basically you just made yourself a Whisper filter, lol. Make sure you keep the bio-bags clean though so that your new "bio-sponges" will remain clean as well. Penguins are awesome and as others have pointed out, aquaclears are nice as well. Here are some pros and cons to each (others please feel free to chime in)
1) Biowheel is an awesome way to keep a good colony of bacteria alive in your tank.
2) The way it is designed, you can remove the filter cartridge without removing or disturbing the biowheel
3) new penguin design allows for a second filter cartridge to be inserted which gives more debris pickup, more carbon, and allows you to stagger the times you change them to keep as much bacteria as possible at once.
4) most people experience very little mechanical problems if maintained correctly.
5) cartridges are simple and easy to replace.
1) cartridges don't hold a lot of carbon
2) overtime the biowheel can collect "sludge" or uneven bacteria buildup which causes it to stop or have irregular turning which can damage bacteria not being exposes to the water.
3) no versatility (though versatility isn't really needed in HOB filters.)
1) generally larger volume and I think more gph than penguins but I could be wrong.
2) more versatility and generally more media (sponge, carbon and bio-media) allowed.
3) just like penguins, very little mechanical problems.
4) Biomedia allows for a lot of surface area (I use it in my canister filter)
5) The media is not in cartridges so you can change sponges and carbon at seperate times.
6) sponges are sturdy and often only need to be rinsed instead of replaced.
1) biomedia must be removed in order to change carbon and sponge. This means you could potentially lose bacteria during filter maintenance.
2) biomedia will collect more debris than a biowheel will.
3) generally a bulkier design than other HOB filters.
4) carbon and sponge being seperate means purchasing media seperately and requires a little more work than a cartridge.
Anyways, those are just things to think about but honestly you will be happy with any of those two decisions. Your other option is canister filters if you have the $$$