I used to re an older Merc Estate (RWD) I had, we have a house in Sweden so they were required if I took the ferry over between October and April when a ferry ran from UK to Scandinavia (Now Netherlands is nearest ferry crossing so tend not to use it for shorter winter holidays, only in summer when winter tyres are not required as it takes nearly 3 days to travel from UK to Sweden by road involving nearly 1000 miles and an overnight ferry)
I had Gislaveds and they were excellent, the road to our house in Sweden is through wooded countryside about 15 miles from the E20 ( main Gothenburg to Stockholm road) and with them on , and possibly 12 inches of snow on our fairly steep driveway and permanent ice on roads, with up to -10 daytime temperatures, the car performed with no issues, up to 35 mph up the back road, with dips and rises, with no feeling it was ever going to lose its footing.
In my experience if you do a lot of winter driving on snow or ice they are worthwhile.