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There is one difference though. In order to be able to send fine-grained updates to the client/browser, those values are 'watched'. That means that whenever you assign a completely new javascript object directly to the property (or if you assign an a new object/array to one of it's sub properties on any level), that new value (reference) you assign will not be 'watched' directly; you have to take/read it back from the property (which will give you a an equivalent 'watched' value) before using it further in code.

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