One thing to keep in mind, is each use is pretty much considered a heat cycle. Really sticky tires have a lifespan that's measured both in tread AND in heat cycles. So something like an F1 tire or a NASCAR tire only gets one heat cycle and is done. Other tires, like ones for competitive Auto-Xers is measured in heat cycles. After a few race weekends the tire will have lost significant grip compared to when new. Now, it'll still be a LOT stickier than a street tire, but significantly slower than a fresh tire.
That's just something to keep in mind when you're buying tires or turning laps. You may get slower each weekend.
ALSO,
Race tires are FAR less forgiving than street tires. That is to say, street tires start howling, and slipping a bit, and generally letting you know that you're pushing them too much. Race tires, on the other hand, will suddenly and dramatically lose traction.