yea...emporer is ridiculas priced. penguin is the way to go, specially between those 2...
The emporer and the penguin are almost the same thing. same manufactorer, same idea for filtration, only difference is emp is rated for 5 or 10 more gallons, uses a different cartridge and costs a ton more....
I've been very happy with all my penguins, and will never spend the extra $$$ for the emps...