<p>There should not be anything wrong with having a TA teach you, and it should be exactly what you expect when you go to a university that has graduate programs. TAs are graduate students and by definition teaching asistants handle discussion or quiz sections--smaller groups within a larger class, with the lecture taught by professors. Some TAs are great teachers, others are not. the same is true at any level of teaching. Almost nowhere would a TA have sole responsibility for teaching a course--if a graduate student is lucky enojgh to have his or her own class to teach it will be with the designation of instructor, not TA. You will know ahead of time who the instructor is before you sign up for the course, so you will know whether it is a professor or an isntructor. </p>
<p>Note too that not all people designated professors have tenure or are even permanent faculty--assistant and adjunct professors are not tenured and may be at any level of teaching skill. Also, being a TA is a fairly desirable thing, so someone who has been trying to get an MA for six years is very unlikely to get pr hold onto a TA-ship at a good school--he or she will be out of the program long before that.</p>