They are ok but I like the bio-wheels because you can change all the filter media and not have to worry about getting rid of the beneficial bacteria because it's on the bio-wheel. People also like the aqua-clear because you can put in lots of media and have things like the bio-wheel. The whispers only have two stage filteration carbon and filter floss thus when you change the media you have to leave some in because beneficial bacteria grows on the media and removes unseen bad stuff in your water keeping your
ammonia,
nitrate,
nitrite levels down, if you remove all of this then you are recycling your tank. So I would not suggest a whisper, either aquaclear or bio-wheel since you can choose what filter media you wish to remove and what to keep.
cheers
atm