I did get one, but I sold it with the tank. However, when I had it, it was very good. A pain in the neck to prime, but once it was set up and running, it was really good. I used fluval ceramic pre filter in the bottom chamber, with a coarse sponge on top, then ceramic bio media, then floss in the top chamber, I had crystal clear water and no ammonia/nitrite issues. So you're not tied to using any specific media (as with most if not all cannisters!).
The only problem other than the priming issue, is that it would be harder to get spares for it, but I never had an issue that would have required any, and plus I only live 15 miles from the guy who sells them on ebay out of his shop in Hemel Hempstead!