I used to think that the most important improvement to our dairy consumption was to buy organic milk, butter and cheese, what with the grow hormones and antibiotics they feed the poor cows these days (and that make it into our body and into the groundwater). But I have had to adjust my thinking. Buying organic butter, and cheese and milk, only assures that the cows were fed an organic (grain - gulp) diet (which is unhealthy for the poor animals and makes them sick). That meat from grass fed cows (their natural diet) is healthier for us than from grain fed or grain finished cows has gradually trickled into mainstream awareness (less fat, more healthy Omega-3, higher in various other micronutrients).
But the same is also of course true for milk, cheese and butter from grass fed cows - much higher levels of vitamin K2 and Omega-3 fatty acids, which actually promote heart health (yes, eat more of it!). Studies have shown that countries where cows are mostly grass fed (Ireland, Australia) have much lower levels of heart disease!
Organic butter really does not buy you much, butter from grass fed cows does.