I run an excalibur on my 55 soon to be reef and it does such a good job of skimming it can even over skim at some points in time. I turn it off every now and then just to let nature take its course for about 4 hours or so. But it has been a great skimmer. Just make sure you clean the tubes and main chamber. Not to mention you must clean the top too. But it has been great otherwise.
I have a 72 Gal bow and run an Excalber. It was designed as a hang on but I run it from my sump. I had to extend the tube from the rio for both the air and water so it would reach. I also got rid of the plastic outflow with the sponge as it looked like it was designed to help eliminate bubbles. I don't have that problem since its going into the sump. It seems to skim fine. But I don't have another frame of reference. It cost me $109 about a year ago.
