Honestly, I'd suggest trying them. I was skeptical but took the plunge a couple of years ago when it started snowing. There's a gentle sloping road near me and where other cars were spinning their wheels to get up, I managed to go up the slope without a hitch. Even in cold weather, I've noticed a difference in grip and performance.
In fact, the only time I've had problems is where the road is so thick with snow, I couldn't travel down it due to clearance issues.