I have a 60L biOrb tropical. My opinion is that are wayyy over priced. So far I've had to replace the pathetic heater and the incredibly noisy airpump. Sooo, the orb cost £150 and I bought the iLight unit (which is actually quite good) for an extra £40. New heater (£15) and a Rena 200 (£20) so that makes £225. Pricey for such a small tank. The ceramic media that is part of the bio filter is useless if you want to keep any bottom-dwellers and IMHO is a very poor media in general. It gets very, very dirty, very quickly and is a swine to clean. Also bear in mind that the tank itself is acrylic and this media scratches it VERY easily. I've replaced the media with pea-sized gravel and it works fine (I did contact reef one about this and they said it wouldn't work!) in fact with the improved air-pump it works a damn-sight better than the 'approved' stuff.
So... Are they worth it? In a word; No. They do look very cool and when they work properly they work very well. My advice; Get a basic cold-water version, use normal aqaurium gravel, buy a decent quality heater and air-pump, do a fishless cycle and eventually you will have a decent tank.
Beware of the algae though. The biorb allows a hell of a lot of light through it. Put it near a window at your peril...
Regards,
DB