Which one of these would be the more relevant feedback?

A tennis player learns to attend to and to correct a next serve on the basis of feedback in the form of:

The"feel"of a serve in good form, that is, the feel of a series of such movements as a firm and correct grip, a swing in the right "groove" and a good follow through. (PE instructors often refer to this form as internal or kinesthetic feedback, the "feel" of one's own muscles moving during the response.)

remarks made by a coach who comments on the quality of various responses, for example, a well- maintained grip, a "groovy" swing or a good follow through.