Haha! Beat ya to it!
Anyway, IMO the best setup would include the emp. 400 and the aquaclear 500.
AquaClear= Excellent Mechanical, problem is if you clean the sponges weekly, you destroy the good bacteria. If you clean them (assuming you have 2 sponges) on a rotation basis, then your nitrates will raise because of the buildup of crap in the older sponge.
Emperor= Excellent BIO and good mechanical. Clean the pads daily and it wont effect the good bacteria. Also reduces nitrates by elimanating the crap (when you clean the pad).
PS: In my emperors, I added the Bio-cartridge to add to the bacteria colonies.
400: works fine.
280: When I added the cartridge, the water overflowed the filter pad and over the cartridge as well. I had to reduce the flow somewhat to use the bio cartridge.
Bio-cartridge: something to add to your filter to increase surface space (LOTS) for the good bacteria to colonize. Some people here say the cartridges are easily breakable when washed. I never had this problem yet. Just handle it carefully, I guess. i could see if you drop it, it would break.