Sump? or Hang-on-tank?

[Go Lions!]

Hi everyone... which in your opinion would be more quiet? a Remora pro haning on a tank skimmer. Or an Aqua C - EV180 skimmer sitting in a 20gal sump under a tank with a 600gal/hr flowrate into/out of the sump. The last one natually sounds like the louder choice, however it would be enclosed in the cabinet. Anyone with experience with sumps, or better yet, ALL-GLASS MEGAFLOW Overflows!!! please reply. Desperately trying to hide the ugly maylay of plumbing/heaters/pumps/skimmer/etc. But CAN'T SACRIFICE A QUIET OPERATION. Thanks!