Currently, if you Add Data and the Feature Classes have Representations applied, then the Layer Properties default to Representations symbology. Although this is probably the most commonly desired function, it would be nice to have the option to have the Layers default to standard "Features" symbology. This was the default at version 9.3.1. Certainly you are able to manually change the symbology in the Layer Properties, however this can be quite cumbersome with a large number of layers.
This option could be added as an unchecked box to the ArcMap Options, on the General tab (General settings), as: "Add Data with Representations using standard symbology". Alternatively, the option could be added to the ArcMap Advanced Settings Utility, on the TOC/Data tab (Working with data).