Third the Deltec. Tinkered with many HOB skimmers and had the pleasure of tinkering with a Deltec MCE600 the other week.
IT IS is by far the easiest to install, service and has the least visual impact of all HOB skimmers as there are no pumps/boxes hanging in the aquarium. As for performance, it's the best HOB skimmer out there.
I've seen the CSS 220 range $169-220UDS and the Deltec MCE600 is $446USD from DeltecUSA...is it worth double the cost? To me definitely considering time in installation, visual impact and skimming performace.
JM2C