Mike, Clarity as a plug-in contains some of the features found in Basic Adjustment, Precision Contrast, and HSL Color Tuning. In Topaz Studio you have two choices. You can build your own "Clarity" by invoking these three adjustment layers through the Adjustments button on the right hand side or from the pull down Adjustments menu in the top bar. The second choice is to scroll down the Styles bar on the left hand of your screen and invoke the Clarity and it populates the left side of with Basic Adjustment, Precision Contrast and HSL Color Tuning.
The beauty of the upgrade and inclusion of Clarity in TS is that there are many more adjustments you to tune your image just the way you want.
Trust this answers your query.