Save/sync HierarchicalDataSource (treeview), having kendo.data.Node models, does not work properly: 
- though setting a kendo.data.Node model, the view model is not applied on all items(e.g. setting the field type), it's applied only on level 0 items
- if modifying a single field on a lower/higher level(e.g. 5th level) in a hierarchycal data source, the entire hierarchy is sent to the server (instead of a single item, probably more than 100 might be sent, thought a single field, on a single item was change)
- when deleting some items, the deleted items are sent as an array (which is ok), but when updating it sends the entire herarchy(see above)
- when creating a lower level item, the create command is not send to the server; only an update on level 0 item (see above)
- there no consistency on what's sent to the server on add/update/delete (e.g. add: level 0 - create; other levels: update on level 0 parent - parent/"grandparent"/...)
- when calling the sync method to save any changes, the model is not updated on succesful save (similar to what's on grid - DataSource), e.g. if server generates an id for the item
- when moving an item from a node to another, destroy command is called, not an update
- on the documentation it says it inherits everything from DataSource, but it seems they do not work properly