No problem,
Sound will be very similar between those two boards, as will the ethernet. MSI's website liks to play up things like "audio boost super-extreme 2.0!," but in reality unless you buy a dedicated sound card you aren't going to be hearing much of a difference.
Both are high-quality boards that will last you a good long time. The real consideration comes down to whether or not you're getting an unlocked 'K' model CPU, and if you want support for 2 graphics cards in the future. If you're not overclocking your CPU and not planning on getting two graphics cards then go with the ASRock Fatal1ty H97.