To be honest, for winter there are better tyres. PS3's don't cope well with snow/ice (they are a summer tyre after all) so it depends on how much driving you want to be able to if the white stuff falls. I'm hoping to swap at least my front 2 before winter arrives.
The only time in 15 years of driving that i've got stuck in snow was last year on these tyres (on a really shallow hill too, with all manor of cars driving by me). I've driven in much worse conditions with 'cheaper' tyres before without issue, so no - it's not my driving before anyone pipes up!