Not either / or, but rather all. Why make a choice? 
One of the best things I have done in this hobby is to do what ever I wanted to do.
Like yourself there are times I just want to let 'em roll. Other times I run commuter service, then mix in some peddler freights. Then there are times when long strings of 80 footers wind through the imaginary countryside.
Then on the top and shortly the bottom level, three rail trains happily chug and whistle along their way.
It's all fun. I do have a pail of mixed rivets sitting in the driveway to keep the naysayers busy outside. 
