RA1's are great dual purpose street/track tires. They don't suffer badly from heat cycles, remaining sticky for pretty much their entire life. Their main weakness is squirmy behavior at full tread. Shaved is the way to go, but this makes the tires less versatile for street use in areas that see rainfall.

 

I've never used PSCs, but I can give you the popular wisdom from the R&C crowd on PSCs vs Toyo RA-1s (which I've used for 3 years).

For track use, shaved (to 4/ or 5/32") RA-1s are the best bet, since they never overheat and stick like glue right up till they're corded. The PSCs last longer on the track but take a while to heat up; you have to thrash 'em to get the most out of them. Once warm they are comparable to RA-1s; over life they tend to "go away" however.

For street use, many people report no problems with RA-1s, claiming 6-8K miles plus several track days per set, even when shaved. Combined with a price that's (usually) much lower than PSCs, the RA-1s are the most commonly recommended. For a street-only car where you just want "a little extra grip", full-tread RA-1s are appropriate, and can be used in wet weather.

Sadly, RA-1s are not available through the Tire Rack (Jim, when are you going to start carrying them?!). My preferred source is Vilven Tire in Royal, IL (800-251-0017, no website); I understand that Les Scwab dealers also carry them.