JD the 500 Credit “Appearance” Option allows you to separate your apparel Abilities (game enhancements) from their Appearance (what you look like) by giving you two separate tabs. You can then chose a set of apparel just for the enhancements and a second set just for how your avatar “looks” like. With this you can also chose all basic items for no enhancements, and still wear items that would give enhancements just for the look.
Also when playing on Mobile/PCEA/Stream you can easily see what your opponents apparel is to verify if they are using enhancements or not by clicking on their profile during a game. There is an Apparel tab that will show the current apparel that they are using for enhancements on a LH column “Stats Gear”. You can click “view specs” for each item to see what its enhancements are. If the player has the Appearance option they will also have a second column of apparel under “Appearance Gear” which is just for the look of their avatar.
You should also be able to do this if you are playing on Flash by opening the App on your phone or loading the PCEA Launcher and going to your friends list and looking at their profile.