question

Yes, the Object class is a subclass of treenode meaning it can do everything a treenode can do, but also expands on it by adding more properties and methods. If you look at the FlexScript Class Reference page in the User Manual you'll see that location property is on the Object class, but not the treenode class. Also on the treenode page you'll find this discussion about the relationship between treenode and Object:

The treenode class is the base class for all objects and nodes accessed in FlexSim's tree. While you can access more data and functionality specific to nodes with object data by using the Object class, treenode is the most basic interface. First, it gives access to data and functionality associated with the tree structure itself. Second, it gives access to basic data stored on the nodes themselves, such as node names and data values. Third, since so much modeling logic uses labels, the treenode class provides a mechanism for easy manipulation of labels on objects, tokens, and task sequences.

The treenode class can be automatically down-cast to a subclass such as Object.

treenode src = model().find("Source1");
Object srcAsObject = src; // auto-down-cast to object

You can also explicitly down-cast using the as() keyword

src.as(Object).location.x += 2;

When FlexScript performs a down-cast, if the node is not a valid instance of the target class type, an invalid cast exception will be thrown.

Object src = model().find("Tools");// throws invalid cast exception
model().find("Tools").as(Object).location.x += 2; // throws invalid cast exception

You can check if a node is a given subclass type with the is() keyword.

if (model().find("Source1").is(Object)) {
	...
}

Thanks @Kaspar Chabot , looks like that is the answer.

@Matt Long:

As I understand there is no way to retrieve the x-location of for instance a source in one line, comparable to the previous -since 17.1 unusable- command xloc(model().find("Source1")) ?

@Matthew Gillespie, but then I get a cast error. Or is this a bug in 17.1?