well I only entered the fandom in late late 2012, so I’m not as good a historian as others could be. But I think the part I miss most was that since the fandom was a little smaller, fans were more cohesive because we competed against other fandoms rather than within ourselves (i.e. directioners vs. beliebers rather than harry girls vs. zayn girls vs. liam girls etc). Not that I ever encourage divisiveness or drama between fandoms because it’s always over a stupid made up reason, but there was more of a sense of community within the 1D fandom itself. people had their faves, sure, but people were less interested in constantly keeping a tally of strikes and balls between faves. at least not that I saw. :/ anyway i mean i’m more glad than mad that the fandom is larger because yay more fans because they deserve it. i just miss that naïveté.
so what i miss is on the fandom side. for the most part (99%) i actually like how the boys have grown older and more mature. the video diaries were cute but i find so much pride in seeing how far they have come as a group, as individuals, and as individuals since X factor.