Re alternative media - try not to get drawn into all of the marketing hype. All media is is somewhere for the beneficial bacteria to grow. The bacteria doesn't care what its growing on. As long as there is enough surface area on that media to support enough bacteria to cope with the waste from your fish, all will be good.
All of the manufacturer's are attempting to sell their product. They will go to extreme lengths to try to show that their product is better than the opposition's for one reason or another. Generally they claim their product is more "efficient" - ie it has more surface area in the same volume. So what??? It just means you need a little bit more of the other product . . . .
For anyone who already has media, I wouldn't recommend changing for the sake of changing. Reality is that provided you have a reasonably sized filter, then whatever media you are currently using is probably already providing far more surface area than required. Adding more surface area will do nothing to improve your filtration. The amount of bacteria will only increase to the level of food (waste) in your tank.
I personally use a whole range of different media in different filters. Basically, I get whatever happens to be the best deal at the time I'm buying. Its when you are setting up for the first time that its worth considering options.
