it has the wow- factor.
in reality the lights are not suited to growing plants, and only plants like java fern, crypts, and maybe some sag species will survive.
the tanks are not too large - they capture the nano market.
the tanks are accessible from that little box on top of the tank. it comes off to reveal a lighting uni with 2 halogens, and a HOB filter.
remove them and there is a small square where you can fit your hand in.
the oxygen problem does not exist as the HOB filter does its job and creates flow, and exposes a certain amount of water to the air. i can imagine having problems if the tank was overstocked, or in the case of a prolonged power cut.
The best thing is that it looks different; and we like different. and you can get them in different colours. a bit like those old imac's in colours. totally useless, but were so different that they were amazingly popular!