I'm surprised you aren't fading your street pads after 5 track days. On my FR-S, the HPS were only marginally better than OEM, and would fade significantly after a couple hot laps around Buttonwillow. But then again Miatas are pretty light..
I don't know about these Hawk Street Race pads. It sounds like a hybrid compound, since they mention dust. Hybrids are fine but if you don't track too often, the dust and the constant care needed to keep them bedded in can be a PITA.
Less than one track day per month? Might be best to have two sets of pads, street and track, and swap between them as needed.