The A5 is a shallow rim, slightly overstable approach disc. The A5 is closest in feel to the Distortion, but will fly straighter with less fade as you break it in.
500 Plastic is a premium blend that has a less gummy feel than 400 plastic. This provides you with an extremely confident grip and a stiffer flight plate, balancing just the right amount of flex and firmness. 500 Plastic has a uniquely pearlescent finish which adds another visual element to each disc.