One large skimmer or 2 medium skimmers?

[lastlight]

I know I've read a few times over the years that 2 skimmers can somehow limit each other and that a single appropriately rated one will out-perform them. I don't recall the rationale but my instinct is to run one.

Having said that I've run across a few amazing large tank builds over at RC running 2 although if I recall correctly they were both high-end skimmers each already rated to handle the user's load.