Speaking from personal experience, as I have been in the process of setting one up for the past six months, there a fantastic self contained system. They require quite a bit of work to set up but once you do there great. Many people have had problems with them in some shape or form mainly with the water levels causing air bubbles with the return pump but once you figure it out its almost worry free. I have also heard of many owners making cuts in the rear dividers to increase the water flow, I have made no such alterations and everything is working great for me. As for inhabitants, I have one clown fish and a variety of zoas, mushrooms, and a red bubble tip anemone. Everything looks great and is doing very well.
The one suggestion that I can make is have two powerheads. I have a Koralia 3 and a 1 running just because although the 3 puts out a lot of flow, with my LR arrangement I always seem to have a dead zone, hence the 1.
Let me know if you want any other info, but trust me you won't be disappointed. And if you are, then you can sell it to me :)