I'm with ya. My buddy has an ST1300 which is smooth as silk, power from hell, handles like a dream and I loved riding it. My K6 is just home to me.
I may "supplement" the fleet at some point with something more modern but I'll never be without a 7 fitty. The human experience is quite complex and I think it's really difficult to chart, measure or test to the point where you can figure out what trips your trigger (as a human).
These ole doggies have something really special going for them. I think a piece of it may be their history... how they forged a new experience in riding and ownership.
It's also important to me that they're "understandable" (I may not be able to diagnose a problem as easily on a newer bike).
Another thing is that there are many avid owners (support group - SOHC4.net) to help when necessary. These folks are worthy of a ton of respect with these bikes and in life.
I tip my hat to the 7 fitty... and as previously alluded to, "if you needs to explains it, they ain't gonna get it". On top of that, analyzing feelings, relationships or nearly anything related to human behavior is "analytical" which by definition is sort of destructive.... so just forget everything I just said