We set out to identify the benefits and drawbacks of using more than one instructor to teach single section science courses at a large research university. Nine courses were investigated involving widely differing subjects and levels. Teaching models included: sequential teaching with two to six instructors each covering only their own modules, two teachers present in class at all times, and hybrids of these two models. A three-question survey was answered by 957 students and 17 instructors. Dominant advantages identified by both groups were "variety of teaching style or perspectives" and "instructor expertise", with instructors being more likely to identify "expertise" as the primary advantage. Dominant disadvantages identified were "adjustment to teaching style and expectations" and "confusion and communication" issues. Data suggest that advantages are maximized and disadvantages minimized either in courses with two or more instructors interacting and collaborating in class or when special care is taken with coordination and collaboration if the course is sequentially taught. We conclude with specific recommendations to instructors and departments based on evidence from the data. (Contains 5 tables and 4 figures.)