I've done 3 winters on Dunlop Graspiks (195/65-15 on a '88 300TE) and they've been fabulous! I did quite a bit of research & solicited a lot of opinions before I bought them. However, I've been given several strong endorsements of the Toyo Observe, which I plan to put on my 500E this winter. I understand both are excellent choices. Watch out for Blizzaks, because the good winter-optimized rubber only lasts for 1/2 the tread depth. Great tires, but you might burn them up in only 1 season.
Sorry, no experience with the Gislaveds.
Best of luck, Michael