Thanks George, very kind as ever! I used to stitch more than I do, and there are pros and cons.
Compared with taking the same shot in one exposure at that aperture, you gain resolution but lose depth of field. Sometimes, as in the Brenizer method, the latter is turned from necessity to virtue. Another issue is that it's harder to compose, particularly when stitching very wide. Also, unless you have a pano head and rotate around what is often called the "nodal point" (although I think this is actually an error), there will be parallax issues with close objects. I got away it with here but I wouldn't recommend it for shooting interiors, for example. Lastly, some people will tell you that stitching longer lenses "changes the perspective". Experimentation with a tripod and taking the same composition at three different focal lengths will soon convince you that is this not true!