Fluidized filters? Merlin v. Lifegard?

Merlin v. Lifegard 300?

Anyone have experience with either or both of these fluidized filters?

I'm considering adding one to my 150g show tank at my office...
probably with a Rio Aqua submersible water pump.

Any comments on build quality, durability, functionality, ease of
setup or maintenance? They both run about $60, plus $16 for the pump.

I'm leaning towards the Lifegard 300 because it seems to have a higher
capacity while hanging snugger behind the tank (I'm doing the hang on
mount).

Here's a link to the site I'm considering purchasing from.
http://www.drsfostersmith.com/produc...=6&pCatId=8756

Thanks in advance.