@heavanet- I have a friend who is from Tibet, and she makes butter tea for special events and holidays for her guests. I have had it with and without milk, and I think that it is definitely best with milk. It certainly does make the butter tea very creamy, and it enhances the flavor.
As the article mentions, this is not the most healthful drink to consume. This is especially true for anyone who is on a low-fat diet, trying to lose weight, or reducing cholesterol intake. Though you certainly wouldn't want to drink butter tea every day, it is a nice, decadent beverage when consumed in moderation or for special occasions.