TeX has a tool called a vphantom that let's you add an invisible structure to an equation that takes up no horizontal space but takes up exactly as much vertical space as it would if it were visible. This is very useful for aligning different parts of an equation for aesthetic purposes. Neither MathType nor Word's equation editor has a similar feature, so I've had to resort to ugly hacks for many years to get things aligned well, and the results usually were usually less than perfect. So of course, I included phantoms in Radical Pie, and you can see a couple examples below where I used them recently. In Radical Pie, you can select any piece of an equation and make a phantom out of it. Then it becomes invisible and has no horizontal size, but it still retains the same vertical extent upward and downward within its subexpression group.

A huge amount of detail goes into mathematical typesetting. These are all the things I have to consider just for a simple radical. radicalpie.com