Cut each rutabaga into quarters; peel, then cut into 1-inch pieces. In 4-quart saucepan, combine rutabagas, enough water to cover, and 1 tsp. salt; heat to boiling over high heat. Reduce heat to mediun; cover and cook until tender, about 15 minutes. Drain.
In food processor with knife blade attached, Combine rutabagas, 2 Tlbs. butter, sugar, and remaining 3/4 tsp. salt, and puree until smooth, occasionally scraping down side with rubber spatula. With processor running, Gradually add milk until blended.
In small saucepan over medium heat., Melt remaining 4 Tlbs. butter; cook, stirring, until golden brown. [do not let burn]
To serve, spoon rutabaga puree into bowl and pour brown butter over.