"Improved" is the wrong word, in my opinion. It's not that the tea is made better with the addition of milk, it's just that it's good in a different way. I drink my tea straight at work, no additions. But on a Saturday morning, with flapjacks and bacon, a lavender earl grey with a hint of sugar and a small splash of cream is just. Mmm. The cream can mute some of the stronger flavor profiles and allow some of the more subtle ones to shine. I love it both ways, neither is better than the other. They're just different good.