This product is great. My filter came with the 3 gallon glofish tank. I own the Tetra Whisper 10i Internal filter (By the way, it takes the medium cartridge, I spent about 20 minutes one day trying to figure out which one fitted in it). It's usually pretty quiet, unless my tank lid shifts and touches the filter, causing the lid to rattle a little.
It is incredibly easy to take apart and clean (I do this about once every 4 months). The filter cartridges are honestly the best part about this thing, you can buy them pre-assembled, in a pack of 1, 3, 8, or 12 packs in a box. You can also buy 12 unassembled in a box (they're really easy to assemble- just wash the green "spine" or center of the filter, and add the carbon-the black stuff- to a fresh white filter bag, rinse well and you're set). I prefer the 12 pack unassembled, because they're cheaper and you don't have to buy them for a whole year (depending on how often you change your filter).
The filters come in several different sizes so make sure you get the right size filter for your tank and ask the sales person what size replacement cartridges it takes, like I said above, mines a 10i, so I can use it on any tank up to 10 gallons, and it's a medium sized bag.