Does achieving jhana give a person an afterglow after the sitting ?  An afterglow of feeling the mind less racing . Being  more in the moment and being more mindful despite putting effort  into it. Just a general feeling of well being.   
.

A general and simple answer to your question is: Yes

Yes. But don't rest on your laurels when you attain it, and don't become overly "entranced" by it. The quieting of the mind is essential to the practice of the vipassana (insight) stage of the practice, which is the stage in which self-transformation and self-realization takes place.

People need to realize that the practice espoused by Gotama had nothing to do with religion or religious practice, but rather with the development and cultivation of wholesome states of mind in the effort to see, recognized, and rid the mind of defilements which cause one's experience of suffering. And which tend to distract the mind from being able to recognize them as such and thus reject them, thereby prolonging their hold, in the form of unwholesome states, on the mind.

In peace,
Ian And