What make these better is a higher stud count, studs on the side knobbles, studs are embedded and won't fall out easily, and they have a lower rolling resistance than full gnarly off-road winter tyres.
Oh, and when Peter White refers to aggressive riding... he means skidding. If you skid a studded tyre on a clear surface you can rip the studs out and damage the tyre such that you lose the benefit. When you're on clear roads, avoid skidding.
Much better are the Nokian W 240.
These can be got from Peter White Cycles who have a great selection of winter tyres: http://www.peterwhitecycles.com/studdedtires.asp
What make these better is a higher stud count, studs on the side knobbles, studs are embedded and won't fall out easily, and they have a lower rolling resistance than full gnarly off-road winter tyres.
Oh, and when Peter White refers to aggressive riding... he means skidding. If you skid a studded tyre on a clear surface you can rip the studs out and damage the tyre such that you lose the benefit. When you're on clear roads, avoid skidding.