I've had studded Duratracs, too - they're very good. IMHO, a true dedicated snow tire is better, but at the same time, the Duratrac DOES have the mountain/snowflake "severe snow" whatever symbol, and the Duratrac is not a "winter only" compound - you can run them year round.
I also think that the Duratrac is slightly BETTER than a dedicated snow tire in untracked/lightly packed snow - FS roads, parking lots, etc. The larger voids seem to dig in better, but...splitting hairs.
Duratracs wear kinda quick, and they're a bit squirmy feeling for the first 100 miles - at which point I'm guessing you just get used to it. Who knows. I towed a 10k# enclosed trailer with my Duratracs, and while I liked my Michelin LTX *better* than the DT, the DT was not bad, at all.
Here in CO, studs are legal year round, so a studded Duratrac is an option, if you want to go with one set winter & summer.