"Mixed use" street/track pads are also known as beginner's pads. They are intended for rookie and first-time track drivers who know that their normal street pads will not hold up in prolonged track environments. The biggest enemy to brakes on a track is heat. Working a pad beyond its temperature range will lead to a loss of performance - aka brake fade. Using a pad with higher metallic and/or ceramic content will improve its resistance to fade at higher temperatures, but at a cost. Unlike strictly-street pads, mixed-use pads need some heat in them to work effectively. Therefore, they are not the best for regular street use. Metallic pads also tend to squeal and produce large amounts of dust. On the other hand, these are not all-out race pads and some fade on the track may occur. If you are experiencing fade with these pads it would be an indication to move up to an all-out race pad and get a brake cooling kit. Street-track pads will be fairly easy on rotors and have long life when kept within their operating temps. These generally also work great as an autocross pad.
Examples of Mixed Street/Track pads we sell are: Hawk HP Plus, Pagid S Sport Pads