Been running this for about 3 months now and love it. The LED lighting is great for my zoas, shrooms, and gsp softies, and my montipora plate is always fully extended. I leave the moonlights on at night (which are more like actinic leds), and bright greens and reds just pop out of the tank, very pretty.
As to the mechanics of the tank, the filter media doesn't cover the entire section. Instead, fill the tank so that with the filter pump on the water line barely reaches the last baffle. This makes sure the filter sits above the water line, forcing water from the overflow into the media. I don't really agree with this approach, but it is what it is. As a side note, this design did allow me to put a submersible heater and air stone (for ph balancing) in the first chamber, opening the middle chamber for a rock rubble refugium. The phophate sponge included with the tank works great; testing regularly, I never see any phosphates, but I've heard after 6mo+ these leech and need to be replaced.
Filter pump is an adjustable 12-53GPH pump, barely making the 10x flow rate for a standard reef tank. I replaced this with a hydor centrifugal pump (160GPH) and placed the filter pump in the tank at half flow for counter current. Immediately saw better polyp extension in all my corals and noticed more detritus in my filter sponge. Cleaning detritus from the filter is a pain, as the baffle chambers are very tiny for big hands like mine and things tend to settle in the smallest middle chamber, but what do you expect from a 4gal?
Lastly, the back of the tank is glass, allowing you to see right into the false wall sump for quick media/equipment checking without disturbing the tank and stirring up detritus. Oh, and doing 1gal water changes is *much* easier than doing 20-40gal on a 200gal tank ^_^.
Overall the lighting, baffled filter system, and a nice glass tank done diy or the like might be only a bit cheaper, and if you're planning on just some softies the pump will do just fine, so overall a nice buy for a great looking pico, but just starting out I'd checkout the 16gal version for stability's sake. Cheers.