I don't know if I quite agree with this. It depends how you do drag and drop. I just bought a MB yesterday and this is only my initial impression.
I find that if you try to select an icon and use the bottom of the trackpad as if it were a button you sometime freeze the mouse because it simulates a two finger gesture. Does that make sense?
If you select the icon and click at the same time it works pretty well. I had to enable the tap click to make me happy.