Hi I have an excalibur on my 75 reef. Good skimmer for the price, I had a prizm and didnt like it so I took it back. The only thing is I got rid of the Rio pump and hooked up a maxi-jet 900 to it instead.
I have to admit I have a red sea skimmer (small 150g) and the first three months I hated it so bad... But now I reaLLY LIKE IT! I have learned to work with it and is really good after your tank is been steady for a while....