This is nothing like the absurdities of the audiophile community. Routing traffic just isn't as trivial as you think it is, and going with cheap NICs that are missing important features and have lower-quality drivers will produce measurable and significant differences in objective benchmarks. If you have something like a 100Mbps cable connection, you can't use just any off-the-shelf hardware and expect to solve any problems in software.
those two boards have more CPU power than my home theater PC... which crunches 720p video all day long without a decent GPU.