[dandelany]

From experience, it may be minor or it may be quite major depending on the shape of your data. If you have a whole bunch of small items that, combined, only account for say 1% of the total, then adding borders and labels to all of them may significantly skew that proportion, and the proportions of its parent/ancestors

[alanbernstein]

Yes, that's true. It depends on your use case. I'm almost always focused on the largest items, e.g. for space recovery. But also, being able to zoom in and out negates that issue in every case for me personally.