My simple answer to the original question is, and I have at times bet safety and success on this, the most important choice when it comes to lubricants is to use the specified weight of oil that the manufacturer recommends. And I mean manufacture or re-builder of engine, transmission, ect. not the brand of vehicle it's in. Everything else is second and can be adjusted for, (i.e. more frequent change intervals).
As this thread has shifted to a synthetic vs conventional discussion here is a video that is a nice introduction if someone isn't familiar with the subject.
I usually put oil discussions in the same category as politics and religion. Even though everyone makes decisions on both, probably best not to discuss in depth with people you want to keep as your friends.
-Eric