The roads where I live become very packed. The plows come sometimes a day or two after the storm.
Cars make the snow almost glacial. So hard that the plows can't scrape it all off until the salt starts working.
With the studs this hard pack is fast and I feel secure at speed. Without studs I have been on my butt.
This is my first set of studded tires and I still have much to learn. (I bought the first pair that I found at the LBS)
After three weeks of riding the Innova tire studs are showing wear from a relatively small amount of pavement.
How soon the studs will become ineffective is yet to be seen. Maybe I can replace the studs with carbide, although haven't found any yet. A bag of 100 standard replacement studs are about $20 online.
Spend the extra $20 and get tire with better (Carbide) studs fright from the start as it is hard to resist riding on the asphalt.