The emperor is a great filter, I had two for about ten years. The company is not very good about warranties though. I had trouble with one, the impeller didn't work after a week. I wrote them to find out how to return it, and they were no help.
I also got tired of hearing that dripping noise all the time and the biowheel squeek once in while. I started using FLUVAL cannister filters and I'll never go back. You have so much control over filter media with a cannister.