What is the intended use case of a RadAjaxManager w/ Ajax requests versus an UpdatePanel/RadAjaxPanel

I'm confused at the benefits of using RadAjaxManager with Ajax requests versus using and UpdatePanel/RadAjax开发者_高级运维Panel. I have both in my solution and it is creating some havoc. What design methodologies are typically deemed best (a bit subjective I realize)

Should I only perform data operations using Ajax and all GUI updates using UpdatePanels/RadAjaxPanels?

Currently I am sometimes updating controls via Ajax manager triggered by ajax request and sometimes a control will postback entirely. If I decide to do everything via Ajax, do I have to make sure nothing ever posts back?

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Check official statement. I think that mixing MS Ajax with Telerik is not a good idea.