Have to admit I'm coming in late on this thread, so I'm sorta responding to Dave's first post.
My model railroads have always been designed to please one customer - me.
Over the years the influence of others (early on in the 70s the RMC V&O series affected my thinking deeply) along with a better understanding of real operations has caused my thinking to evolve (my 1st layout was in HO with a loop and a couple sidings on a 4X8 sheet of plywood).
Like Dave I'm a railfan and there are times when just watching the train "snake" around (at eye level!) is all I want to do. But I also learned that alone can become boring. So my track plans increasingly have been designed to accomodate operations that resemble what real trains might do (albeit compressed).
Recent layout designs (recent for me is the last 15 years

) have multiple train operator capability. But for the most part it's mainly me running the things.
My take on operations (locals, yard assignments, etc) is still done with a "free form" approach, sort of like the way I approached play as a kid. The card systems etc seem way too rigid for me and remind me too much of "work".
I was in a HO club as a teenager but unfortunately before we got out layout to the point of operations we got booted out of the trolley museum. :

I have an open mind about the structured train running though, and hope to take up one of Lee's invites to observe this sort of thing in person to see what it's really about.

My current layout is rather smaller than I want due to the kids taking priority in the limited amount of space in my house, but I'm already thinking about the next layout. I want it "bigger" but not in a spaghetti bowl sort of way. Most of the increase in size will be in the interval between "switching points" (towns, mines, etc). I do not want to create a maintenance nightmare!