The answer of this question depends on the requirements of your project. Generally speaking, the widgets incorporate templates as well as several other features such as selection, editing, paging and etc. If you need those extra features, probably it would be better to use a widget.
Templates on the other hand are simpler, easily configurable and in some cases easier for initialization. My suggestion is to test both approaches and decide which one fits better in your specific case.
the Telerik team
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