The psText property is a recursive concatenation (if I remember correctly) of all the NodeValues of the text type child nodes of the node object you ask. Care should be taken if you don't know the exact sub-structure of the node. You could also get the psNodeValue of the first child, the n'th child or the last child, in case the node may have more than a simple text node as the only child. The last is the situation for this fragment <somenode>Some-text</somenode>.

psNodeValue returns different values depending on the type of the node. For the most common types it returns nothing. There is a nice overview here, at MSDN.

The documentation could do with some kind of warning that psNodeValue may not return what you want, unless the node is actually a text node. And that a named node containing text is not itself a text node. And point to the psText property for the typical use cases.