The interesting thing about this thread, as with many, is that there are people expressing opinions with no real life experience.
The only way of making a comparison between winter and summer tyres is if you have had experiences with both in different conditions. The idea of keeping distance and driving at a safe speed is not enough to always keep you out of a ditch.
I understand there are many drivers here who have been driving for years, even decades, with no snow related accidents. I did for the first 10 years of driving. That said, I have experienced and witnessed enough to know that winter tyres are the best option on snow.
Most memorably was a trip from here to Brussels airport - a drive of normally no more than 2 hours - that took 4.5 hours. The snow was hammering down just after I left, and by the time I was driving through the Ardennes in Belgium, it was completely covered and packed down solid. ((It has to be said that the Ardennes is a micro-climate all to itself (I slipped on ice in a parking area in July a few years ago). If you're reading this, Tunnie, this is your route to Luxembourg, should you take the quickest and most logical).
In this case I was in a Granada (RWD). Down hill on a motorway in 1st/2nd gear. I saw all manner of cars, SUVs, vans, just randomly sliding down the hill, sideways, backwards, forwards. All going very slowly - no more than 10mph. No amount of steering, braking was going to help. It was plainly obvious which cars had summer tyres and which had winter.
This is just one example of many. But it is a fact that winter tyres give more traction on snow and can be the difference between a ditch/fence/hedge or not.
The idea that "I am not buying tyres for 2 weeks use a year" is also nonsense. Winters stay on the car for 4-6 months, so in that time, you are not wearing out the summers. So once the initial cost is covered, then there is no difference.
I once rescued someone from a hill on snow. My car on winters, hers on summers. She got stuck on a junction on a hill. Could not go up - no traction. Too frightened to go down - understandably so. The moment you let the clutch out the car went sideways. Anyway winter tyres on mine. Slippery, yes. Impossible, no.
With all that said, I would also say, that if you can avoid having to buy winters for just what may be a few days of snow, then great. But if, like me, you have them on from October, you can relax. No matter what mother nature sends, you are as prepared as you can be. No panic when a few flakes fall - you just go out as normal - just slower.