Thanks Ray, That is actually part of my point. I just forgot to elaborate.
A generous overlap gives you many options to overcome possible issues in the final stitch.
For instance, my primary usage of stitching is to get a wider view than a 24mm (with DSLR, 47mm with 6x9 on film) when shooting interiors on commercial assignments. Usually all I do is a left then right shift with no pan at all. The overlap is huge (like 50%) and 95% of the time CS3 handles it perfectly, but about 5% of the time gets a bit confused with some funny things going on in the graded tones of the ceilings. Then I simply pre-crop the images with a smaller overlap at various locations to get a smother transition in the ceiling and it works out fine.