This is a refreshing--and valuable piece.  Thanks for this!

"In terms of overall retirement happiness, a solid marriage can be just as valuable as ..."
In case those on the cusp of retirement read that, shrug and say, "well, our marriage is solid, so..."  Think again.

How solid was your marriage when the stress of a first newborn rose up to challenge it?  How solid was your marriage when somebody close began behaving irrationally and was diagnosed with a mental illness?  How solid, when someone near and dear suddenly died  "way too soon"?  
These are huge challenges, and for many couples so is retirement.  Some "solid" marriages resemble those based on quicksand. Warning: you will be tested--sometimes significantly, when one (or both!) of you stops working. State priorities clearly BEFORE retirement.  Talk about fears.  Tough stuff, especially if SHE is all set to go travelling ("now that we have the time...") and he secretly dreads life "beyond the office/plant/business."  'fess up!