Ditto on airports as waypoints. We use them ALL THE TIME.
I have been studying this for years and did some math averaging...
On a typical 200 mile X-C leg, we use 3-4 equidistant airports as waypoints. I have found that this typically adds only 5-7 nautical miles per 200 mile journey.
However, the safety factor is worth it. At any give time, should we have a minor problem, we only have to make one decision - keep going or turn 180 degrees. Either way, we are only minutes from a viable airport to get it on the ground. This works especially well when encountering weather we are not sure about....always giving ourselves an "out."
Naturally a catastrophic IFE would have one of us landing anywhere ASAP, but having airports along the way is a great comfort when traversing unknown territory (for me and my caravans of multiple planes).
Great discussion, thanks! Mike Marra, Keystone Flight